fix: allow comments to contain --

[jablko]

This change allows comments to contain --, which currently they can't, e.g.

<!-- eslint-disable-next-line no-console -- Here's a description about why this configuration is necessary. -->

  1:1  error  Block is redundant  no-lone-blocks

I suspect this is already fixed in #284, by upgrading to micromark. This PR adds a test and patches the comment regexp in the meantime.

remark-parse (where this regexp originally came from) went directly from our current regexp to micromark, which doesn't use an equivalent.

I used the following to automatically construct this corrected, "strings that don't contain -->" regexp, substituting aab for --> because it only allows alphanumerics, etc.: http://www.formauri.es/personal/pgimeno/misc/non-match-regex/?word=aab

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[codecov-commenter]

Codecov Report

Merging #348 (bdf53c1) into master (29ba0c5) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #348   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           21        21           
  Lines          507       507           
  Branches       109       109           
=========================================
  Hits           507       507           

Impacted Files	Coverage Δ
packages/eslint-mdx/src/regexp.ts	100.00% <100.00%> (ø)

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[JounQin]

Wow, it's cool, thank you!

[ChristianMurphy]

👍

[JounQin]

cc @wooorm

[wooorm]

✅