Revert "Make apostrophes not brackets in markdown (#46414)" (#47396)

This reverts commit d1b18fbaed.


https://github.com/zed-industries/zed/commit/8cd3bd90aaf6aff809d3962e9ca67d1548d50dc9
was landed interim which has a test that's broken now.

Something-something build queue.

Closes #ISSUE

Release Notes:

- N/A

crates/languages/src/markdown/brackets.scm

@@ -3,4 +3,5 @@
 ("{" @open "}" @close)
 (("\"" @open "\"" @close) (#set! rainbow.exclude))
 (("`" @open "`" @close) (#set! rainbow.exclude))
+(("'" @open "'" @close) (#set! rainbow.exclude))
 (((fenced_code_block_delimiter) @open (fenced_code_block_delimiter) @close) (#set! rainbow.exclude))