message: Highlight (begin|end){macrocode} in dtx files
diff: <key>name</key>
  <string>meta.function.verb.latex</string>
  </dict>
  + <dict>
  + <key>begin</key>
  + <string>(?:\s*)(\\begin\{macrocode\})</string>
  + <key>captures</key>
  + <dict>
  + <key>1</key>
  + <dict>
  + <key>name</key>
  + <string>keyword.other.macrocode.dtx</string>
  + </dict>
  + </dict>
  + <key>end</key>
  + <string>(\\end\{macrocode\})(?:\s*\n)?</string>
  + <key>patterns</key>
  + <array>
  + <dict>
  + <key>include</key>
  + <string>$base</string>
  + </dict>
  + </array>
  + </dict>
  <dict>
  <key>include</key>
  <string>text.tex</string>
  