Added third party library to doc.

[SantoshPisini]

Rendered article section for review:

• Using the Microsoft Edge Add-ons API > Library Support - adds 2nd row in table
  • Internal review: https://review.learn.microsoft.com/microsoft-edge/extensions-chromium/publish/api/using-addons-api?branch=pr-en-us-3087#library-support
  • GitHub public preview
  • Before/Live

This PR adds a table row containing a link to the NuGet package https://www.nuget.org/packages/SantoshPisini.EdgeAddonsAPI.

AB#49260400

[learn-build-service-prod[bot]]

Learn Build status updates of commit 4a395fd:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
microsoft-edge/extensions-chromium/publish/api/using-addons-api.md	:white_check_mark:Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[learn-build-service-prod[bot]]

Learn Build status updates of commit abaadb1:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
microsoft-edge/extensions-chromium/publish/api/using-addons-api.md	:white_check_mark:Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel