docs: setting up dev containers

[ThEditor]

Summary

• Enabled sphinx.ext.autosectionlabel to link sections
• Mentioned the two ways of dev environment setup - host, devcontainers.
• Created a guide on setting up devcontainers

Reviewer guidance

Build the docs using make docs and open localhost:8888 to check the updated documentation.

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Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[vkWeb]

@ThEditor this is marked as draft, is it ready for review or you are gonna be making more changes?

[ThEditor]

Woops, forgot to mark it ready for review.

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.0.dev0_git.20231221060538.pex
Windows Installer (EXE)	kolibri-0.16.0.dev0+git.20231221060538-unsigned.exe
Debian Package	kolibri_0.16.0.dev0+git.20231221060538-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0.dev0+git.20231221060538-0.3.0.dmg
Android Package (APK)	kolibri-0.16.0.dev0+git.20231221060538-0.1.0-debug.apk
TAR file	kolibri-0.16.0.dev0+git.20231221060538.tar.gz
WHL file	kolibri-0.16.0.dev0+git.20231221060538-py2.py3-none-any.whl

[vkWeb]

I appreciate your thought process about keeping the old docker instructions and marking it as legacy. Overall nice work.

I'll make further edits on top of your documentation and I will soon let you know about the final product.

@ThEditor merged your PR, thanks man!

[vkWeb]

I have edits on top of your docs here -- learningequality#11443.