docs: Move bigbluebutton-docs to the main repository

[GhaziTriki]

Background

During BigBlueButton Developer Summit XVI held in Berlin, Germany from Nov 28 to Dec 2nd of year 2022, the community decided to rework the official documentation to make it better.

The initial work has been done in the following repository https://github.com/riadvice/bigbluebutton-docs

Contributors

This work could not be possible without the direct help of (in the contribution order):

• @JeanPluzo: New structure of the docs.
• @lkiesow: Multi-version build script and suggestion to merge to the main repository.
• @danimo: Improvement the build script.

What does this PR do?

Move the official documentation with its actual content but reworked structure to the main repository.

Motivation & Context

The current documentation lacks of:

• Clarity: only one menu and no clear scopes separation (users, dev, administration...)
  → The new documentation is now split in 6 main sections.
• Search: No embedded search engine
  → A search engine is now included.
• Correlation: The docs are decorrelated from the development, not everything is documented in time.
  → Documentation is now part of the main repository. Development and feature documentation should go more in parallel.
• Multi-version: Multiple version maintenance happens on the same branch.
  → Each version is now maintained in its own branch.

Tasks

Required for merge

• Multi-version build script
• Move old doc pages
• Per section menu
• Update broken links
• Update markdown heading title (h1, h2..) to match docusaurus requirements.

Nice-to-have

• Github Actions configuration.
• Create a readme about how to run docs in dev environment.
• Custom icons, colours and layout.

To do later

• Update Greenlight v2 and replace them with Greenlight v3
• Merge updates from the old docs repo after commit 8cfdcde8

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
2 Code Smells

No Coverage information
1.7% Duplication

[antobinary]

(Note to self/Ghazi) We'll likely need to copy over any docs changes from https://github.com/bigbluebutton/bigbluebutton.github.io/commits/master
that have taken place since ~ Nov 30, 2022

[sonarcloud]

SonarCloud Quality Gate failed.   

1 Bug
0 Vulnerabilities
0 Security Hotspots
4 Code Smells

No Coverage information
1.7% Duplication

[zhem0004]

• Why do we need "backup" folder with starter template files?
• (allow execution on build script)
• Teaching guide still to be done
• Fix main page buttons in dark theme

• Highlight of what section you are at in dark theme is very hard to see
• "next" buttons on bottom of pages run you in circles

[antobinary]

Just talking with @danimo @schrd @tibroc and others and the consensus is that the work in this PR is a huge leap forward in a desired direction. BIG Thanks to @GhaziTriki @JeanPluzo @lkiesow @danimo and anyone else who has contributed.

Merging this will allow others to contribute more easily even while this docs version is being built.