Please consider to remove illegal strings in syntaxes

[stone-zeng]

Although "..." and '...' may be considered to be not correct in LaTeX document, people often use it for message/log and Lua code, see e.g.

• From https://github.com/latex3/latex3/blob/master/l3kernel/l3msg.dtx

  \__kernel_msg_new:nnnn { kernel } { enable-debug }
  { To~use~'#1'~load~expl3~with~the~'enable-debug'~option. }
  {
     The~function~'#1'~will~be~ignored~because~it~can~only~work~if~
    some~internal~functions~in~expl3~have~been~appropriately~
    defined.~This~only~happens~if~one~of~the~options~
     'enable-debug',~'check-declarations'~or~'log-functions'~was~
    given~when~loading~expl3.
  }

• From https://github.com/FrankMittelbach/fmitex/blob/master/doc-v3/doc.dtx

    \cs_if_exist:NTF #1
      {
        \__doc_trace:x{Indexing~ '#3'\space as~ 
                       \tl_use:N \l__doc_idxtype_tl }
        #1{#2}{#3}
      }
      {
        \PackageError{doc}{Doc~ element~
           '\tl_use:N \l__doc_idxtype_tl'~ unknown}%
  
          {When~ using~ '\string\RecordIndexType'~ the~ type~ must~ 
           be~ known~\MessageBreak
           to~ the~ system,~ i.e.,~ declared~ via~ 
           '\string\NewDocElement'\MessageBreak
           before~ it~ can~ be~ used~ in~ indexing.}
     }

• From https://github.com/wspr/fontspec/blob/master/fontspec-code-msg.dtx

  \@@_msg_new:nnn {fontspec} {icu-feature-not-exist-in-font}
  {
  OpenType feature '\l_keys_key_tl=\l_keys_value_tl' (#1) not available
  for font '\l_fontspec_fontname_tl'
  with script '\l_@@_script_name_tl' and language '\l_@@_lang_name_tl'.
  }

• From https://github.com/wspr/fontspec/blob/master/fontspec-code-opentype.dtx

        \lua_now:e { fontspec.check_ot_script("\l_@@_tmp_tl", "#2") }

So please consider to remove the following rules (to avoid the red background in github):

https://github.com/textmate/latex.tmbundle/blob/404e0049b67d54c2733b5a16eb600740c4ec2e19/Syntaxes/LaTeX.plist#L1626-L1637