Update readme & docs

[irongut]

Bug Report

Installation method is out of date in Readme & docs. Update with instructions for using the Nuget from GitHub Releases. Instructions for nuget.org can be added later.

Add documentation at namespace level including a description of the purpose of the namespace with links to any relevant external documentation. See StackOverflow.

Additional Context

All manually generated sections of the docs & readme should be updated.

Include a mention of debugging with Source Link, etc.

Linked To

68 Add links to API docs

73 Improve debugging experience

[irongut]

Tasks

• [x] Add namespace documentation. (#68)
• [x] Add EDSM API links to classes. (#68)
• [x] Readme: update library description.
• [x] Readme: update installation method.
• [x] Readme: Add a section on Source Link.
• [x] Update docfx_project/index.md and docfx_project/api/index.md like Readme.
• [x] Update docfx_project/articles/how-to-contribute.md?
• [x] Rework doc comments to be more consistent in style:
  • [x] BGS
  • [x] Common
  • [x] EDSM
  • [x] Exceptions
  • [x] GalNet
  • [x] INARA
  • [x] Network
  • [x] Platform
  • [x] Powerplay
• [x] Add details of exceptions thrown to relevant methods.

[irongut]

Source Link

Include a description of Source Link and how to enable it in VS2019.

Source Link Repo Source Link Docs How to configure Source Link in VS Hanselman Source Link Blog