docs(contributing.md): Correct typos and sentences

Author: alecgerona

docs/contributing.md

@@ -8,13 +8,13 @@ If you're a first-time contributor, you can check the issues with [good first is
 
 ## Before making a pull request
 
-1. Fork [the repository](https://github.com/commitizen-tools/commitizen)
-2. Clone the repository from you GitHub
-3. Setup development environment through [poetry](https://python-poetry.org/) (`poetry install`)
-4. Check out a new branch and add your modification
-5. Add test cases for all your changes  
+1. Fork [the repository](https://github.com/commitizen-tools/commitizen).
+2. Clone the repository from your GitHub.
+3. Setup development environment through [poetry](https://python-poetry.org/) (`poetry install`).
+4. Check out a new branch and add your modification.
+5. Add test cases for all your changes.
    (We use [CodeCov](https://codecov.io/) to ensure our test coverage does not drop.)
-6. Use [commitizen](https://github.com/commitizen-tools/commitizen) to do git commit
-7. Run `./scripts/lint` and `./scripts/test` to ensure you follow the coding style and the tests pass
-8. Update `READMD.md` and `CHANGELOG.md` for your changes
+6. Use [commitizen](https://github.com/commitizen-tools/commitizen) to do git commit.
+7. Run `./scripts/lint` and `./scripts/test` to ensure you follow the coding style and the tests pass.
+8. Update `READMD.md` and `CHANGELOG.md` for your changes.
 9. Send a [pull request](https://github.com/commitizen-tools/commitizen/pulls) 🙏