docs(external_links): add talks, articles section to external_links

[Lee-W]

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Types of changes

Please put an x in the box that applies

• Documentation Update

Description

Describe what the change is

Checklist:

• Add test cases to all the changes you introduce
• Run ./script/lint and ./script/test locally to ensure this change passes linter check and test
• Test the changes on the local machine manually
• Update the documentation for the changes

Steps to Test This Pull Request

mkdocs serve
http://127.0.0.1:8000/external_links/

Expected behavior

External Links page exists

Related Issue

If applicable, reference to the issue related to this pull request.

Additional context

#208

[codecov]

Codecov Report

Merging #213 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #213   +/-   ##
=======================================
  Coverage   95.64%   95.64%           
=======================================
  Files          34       34           
  Lines         942      942           
=======================================
  Hits          901      901           
  Misses         41       41           

Flag	Coverage Δ
#unittests	95.64% <ø> (ø)

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