remove custom board url

Author: Hannes7eicher

content/hardware/03.nano/boards/nano-matter/tutorials/01.user-manual/content.md

@@ -121,11 +121,7 @@ For low-power consumption applications, the following hacks are recommended:
 
 ### Install Board Core and Libraries
 
-The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **File > Preferences** and in the **Additional boards manager URLs**, add the following:
-
-`https://siliconlabs.github.io/arduino/package_arduinosilabs_index.json`
-
-Now navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
+The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
 
 ![Installing the Silicon Labs core in the Arduino IDE](assets/bsp-install-2.png)
 

content/hardware/03.nano/boards/nano-matter/tutorials/02.getting-started-matter-display/getting-started-matter-display.md

@@ -86,11 +86,7 @@ We are going to use the Arduino IDE to develop around the Nano Matter Display. F
 
 ### Board Core and Library Installation
 
-The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **File > Preferences** and in the **Additional boards manager URLs**, add the following:
-
-`https://siliconlabs.github.io/arduino/package_arduinosilabs_index.json`
-
-Now navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
+The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
 
 ![Installing the Silicon Labs core in the Arduino IDE](assets/bsp-install-2.png)
 

content/hardware/03.nano/boards/nano-matter/tutorials/03.matter-fan/content.md

@@ -55,11 +55,7 @@ Download the complete project code [here](assets/matter_fan.zip).
 
 ### Board Core and Libraries
 
-The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **File > Preferences** and in the **Additional boards manager URLs**, add the following:
-
-`https://siliconlabs.github.io/arduino/package_arduinosilabs_index.json`
-
-Now navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
+The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
 
 ![Installing the Silicon Labs core in the Arduino IDE](assets/bsp-install-2.png)
 

content/hardware/03.nano/boards/nano-matter/tutorials/04.matter-relay-lightbulb/content.md

@@ -57,11 +57,7 @@ Download the complete project code [here](assets/matter_smart_relay.zip).
 
 ### Board Core and Libraries
 
-The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **File > Preferences** and in the **Additional boards manager URLs**, add the following:
-
-`https://siliconlabs.github.io/arduino/package_arduinosilabs_index.json`
-
-Now navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
+The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
 
 ![Installing the Silicon Labs core in the Arduino IDE](assets/bsp-install-2.png)
 

content/hardware/03.nano/boards/nano-matter/tutorials/05.matter-rgb-light/content.md

@@ -55,11 +55,7 @@ Download the complete project code [here](assets/matter_rgb_light.zip).
 
 ### Board Core and Libraries
 
-The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **File > Preferences** and in the **Additional boards manager URLs**, add the following:
-
-`https://siliconlabs.github.io/arduino/package_arduinosilabs_index.json`
-
-Now navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
+The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
 
 ![Installing the Silicon Labs core in the Arduino IDE](assets/bsp-install-2.png)
 

content/hardware/03.nano/boards/nano-matter/tutorials/06.matter-temp-sensor/content.md

@@ -55,11 +55,7 @@ Download the complete project code [here](assets/matter_temperature_sensor.zip).
 
 ### Board Core and Libraries
 
-The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **File > Preferences** and in the **Additional boards manager URLs**, add the following:
-
-`https://siliconlabs.github.io/arduino/package_arduinosilabs_index.json`
-
-Now navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
+The **Silicon Labs** core contains the libraries and examples you need to work with the board's components, such as its Matter, Bluetooth® Low Energy, and I/Os. To install the Nano Matter core, navigate to **Tools > Board > Boards Manager** or click the Boards Manager icon in the left tab of the IDE. In the Boards Manager tab, search for `Nano Matter` and install the latest `Silicon Labs` core version.
 
 ![Installing the Silicon Labs core in the Arduino IDE](assets/bsp-install-2.png)