Developer documentation updates

[MisRob]

Summary

Couple of updates of developer documentation How To Guides in response to volunteer work + small cleanup.

• Adds Preview Kolibri on a mobile device, a new guide for previewing Kolibri in web app mode on simulated and real mobile devices
• In Running Kolibri with local Kolibri Design System, highlights the warning about relative vs absolute KDS path by formatting it as such
• In the Getting started -> Sample resource and data, adds a link to reference the Kolibri user guide on importing with token.
• Makes heading levels across all How To guides consistent

Reviewer guidance

• Preview the links above
• Confirm that both options to run Kolibri on a real mobile device work as expected when following step by step

Comments

@nucleogenesis @rtibbles I am not entirely sure how pre-existing https://kolibri-dev.readthedocs.io/en/develop/manual_testing/app_plugin/index.html fits into the mobile device landscape. Does this command simulate Android? If so, should we cross-reference with the new mobile device guide, or place these two pages close to each other, or even have on a single page? And how should I best explain in what cases app plugin is preferred?

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Build Artifacts

Asset type	Download link
PEX file	kolibri-0.18.0.dev0_git.20241115202159.pex
Windows Installer (EXE)	kolibri-0.18.0.dev0+git.20241115202159-windows-setup-unsigned.exe
Debian Package	kolibri_0.18.0.dev0+git.20241115202159-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.18.0.dev0+git.20241115202159.dmg
Android Package (APK)	kolibri-0.18.0.dev0+git.20241115202159-0.1.4-debug.apk
TAR file	kolibri-0.18.0.dev0+git.20241115202159.tar.gz
WHL file	kolibri-0.18.0.dev0+git.20241115202159-py2.py3-none-any.whl