docs: Extend and refactor index of further kernel docs

Extend the Index of Further Kernel Documentation by adding entries for the
Rust for Linux website, the Linux Foundation's YouTube channel, and notes
on the second edition of Billimoria's kernel programming book. Also,
perform some refactoring: format the text to 75 characters per line and
sort per-section content in chronological order of publication.

Signed-off-by: Carlos Bilbao <carlos.bilbao.osdev@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20240622194727.2171845-1-carlos.bilbao.osdev@gmail.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>