Split the toolchain setup into separate docker and native pages
and improve instructions to better refer to Zephyr docs in certain steps.
Also refactor to improve consistency and add virtualenv instructions.
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Co-authored-by: KemoNine <mcrosson@kemonine.info>
Co-authored-by: Cem Aksoylar <caksoylar@users.noreply.github.com>
Updated the keymap upgrader to highlight which lines it changed as well
as indicate when nothing needed to be upgraded.
Also adjusted the line highlight colors to be more readable in both
light and dark color schemes.
