message: Update scope selectors for syntax highlighting
diff: <key>0</key>
  <dict>
  <key>name</key>
  - <string>keyword.other.macrocode.dtx</string>
  + <string>support.class.dtx</string>
  </dict>
  </dict>
  <key>end</key>
  <key>1</key>
  <dict>
  <key>name</key>
  - <string>support.class.guard.dtx</string>
  + <string>entity.name.function.filename.latex</string>
  </dict>
  </dict>
  <key>match</key>
  