Pioneer DDJ-200: updated documentation

[absorb-it]

Updated documentation for additional features like loop and jump coming with mixxxdj/mixxx#15402

[absorb-it]

Unclear how to fix this, 3 of 4 hyperlink targets had been already in the original:

Check RST syntax.........................................................Failed
- hook id: rstcheck
- exit code: 1

source/hardware/controllers/pioneer_ddj_200.rst:1: (INFO/1) Hyperlink target "pioneer-ddj-200" is not referenced.
source/hardware/controllers/pioneer_ddj_200.rst:34: (INFO/1) Hyperlink target "pioneer-ddj-200-decks" is not referenced.
source/hardware/controllers/pioneer_ddj_200.rst:67: (INFO/1) Hyperlink target "pioneer-ddj-200-pads" is not referenced.
source/hardware/controllers/pioneer_ddj_200.rst:102: (INFO/1) Hyperlink target "pioneer-ddj-200-mixer" is not referenced.
Error! Issues detected.

[ronso0]

Never mind. A lot of these warnings are thrown for many pages.
Seems to be an issue with rstcheck, or rather the docutils dependency
rstcheck/rstcheck#77