[DOCS] Remove Multi-dimensional array FAQ

[ChrisChinchilla]

As part of #1219 I feel this already covered in type docs now and doesn't need the explicit FAQ item.

Checklist

• Code compiles correctly
• All tests are passing
• New tests have been created which fail without the change (if possible)
• README / documentation was extended, if necessary
• Changelog entry (if change is visible to the user)
• Used meaningful commit messages

[codecov]

Codecov Report

Merging #5789 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #5789   +/-   ##
========================================
  Coverage    88.27%   88.27%           
========================================
  Files          340      340           
  Lines        33011    33011           
  Branches      3964     3964           
========================================
  Hits         29142    29142           
  Misses        2517     2517           
  Partials      1352     1352

Flag	Coverage Δ
#all	88.27% <ø> (ø)	⬆️
#syntax	28.35% <ø> (ø)	⬆️