- Still to be "ported" over and cleaned up from the PoC is the
  section on installing Java.

- The FAQ also has some of the older content commented out with a
  planned return when brain starts working again properly.

- Not all feedback has been acted on yet and one change in particular
  (on finding a terminal emulator-like app) could already benefit
  from being moved/refactored.

Changes:

- Remove old `userguide/docs/faq.md.orig`

- Remove extranous `.` at end of sentence in `userguide/docs/faq.mdx`

- Attempt to improve wording of first section in `userguide/docs/java.mdx`

- De-pluralise `applications` in `userguide/docs/java.mdx`

- Add initial section on install headless server to `userguide/docs/installer.mdx`

Changes:

- Rename `*.mdx` to `*.md` where inline Javascript isn't used

- Add missing `Installing Java` section to `userguide/docs/java.mdx`

- Fix a few typos and try to reduce repition in various places

- Add section on which version of Java to install to `userguide/docs/java.mdx`

- Add section on installer log file to `userguide/docs/faq.md`

- Reinstate and re-word commented-out section on driver troubleshooting
  in `userguide/docs/faq.md`

- Add some inline HTML comments on things to consider documenting

- Add initial article on launchers and mod managers

- Various other little tweaks, because OCD...