Merge branch 'sg/diff-indent-heuristic-non-experimental'

We promoted the "indent heuristics" that decides where to split
diff hunks from experimental to the default a few years ago, but
some stale documentation still marked it as experimental, which has
been corrected.

* sg/diff-indent-heuristic-non-experimental:
  diff: 'diff.indentHeuristic' is no longer experimental

diff --cc Documentation/config/diff.txt
Simple merge