Add Giscus comments system

[fflaten]

Implements Giscus as comment system for all Docs and Commands-pages. Only index-page is currently excluded.
Comments are stored and managed as discussions in specific category in the docs-repo.

Fix #251

TODO:

• Install Giscus app in docs-repo
• Enable discussion in docs-repo. Remove default categories and create a "Comments" or "Website Comments"-category of Announcement-type
• Update config
• Reswizzle after Docusaurus v3 upgrade Docusaurus v3 #272

[bravo-kernel]

Looks amazing. Perhaps comments could also be excluded for the Additional Resources section but to be honest, I think that whole section should either be dropped or totally reworked anyway. It's just a lot of very (years old) content for which a google search provides better results.

[fflaten]

Great minds. See #264 😁
Until then, comments to help crowdsource what works or not is an improvement.

[fflaten]

A few sample pages:

• Multiple threads incl. a long thread: https://deploy-preview-267--pester-docs.netlify.app/docs/commands/Add-ShouldOperator
• Locked discussion: https://deploy-preview-267--pester-docs.netlify.app/docs/contributing/introduction

What do you think @nohwnd?

[bravo-kernel]

LGTM shall we just merge this?

[fflaten]

Can't, see task list in PR details. Using my fork's discussion atm. So waiting on approval and actions from @nohwnd 🙂

[bravo-kernel]

Ahhh 🤦🏻