message: Add syntax highlighting for \mint
diff: @@ -1820,6 +1820,50 @@ Put specific matches for particular LaTeX keyword.functions before the last two
  <key>name</key>
  <string>meta.function.verb.latex</string>
  </dict>
  + <dict>
  + <key>captures</key>
  + <dict>
  + <key>1</key>
  + <dict>
  + <key>name</key>
  + <string>support.function.verb.latex</string>
  + </dict>
  + <key>2</key>
  + <dict>
  + <key>name</key>
  + <string>punctuation.definition.function.latex</string>
  + </dict>
  + <key>3</key>
  + <dict>
  + <key>name</key>
  + <string>punctuation.definition.arguments.begin.latex</string>
  + </dict>
  + <key>4</key>
  + <dict>
  + <key>name</key>
  + <string>punctuation.definition.arguments.end.latex</string>
  + </dict>
  + <key>5</key>
  + <dict>
  + <key>name</key>
  + <string>punctuation.definition.verb.latex</string>
  + </dict>
  + <key>6</key>
  + <dict>
  + <key>name</key>
  + <string>markup.raw.verb.latex</string>
  + </dict>
  + <key>7</key>
  + <dict>
  + <key>name</key>
  + <string>punctuation.definition.verb.latex</string>
  + </dict>
  + </dict>
  + <key>match</key>
  + <string>((\\)mint)(\{)[a-zA-Z]*(\})([^a-zA-Z])(.*?)(\5)</string>
  + <key>name</key>
  + <string>meta.function.verb.latex</string>
  + </dict>
  <dict>
  <key>match</key>
  <string>\\(?:newline|pagebreak|clearpage|linebreak|pause)(?:\b)</string>
  