Sounds good.
Would this be an / (is this the) idea:
If the user elects to use the addin.
The addin inserts a menu option, say,
syntax highlighting, under, eg, the tools menu.
The addin enables, first time, a default pref file preset for common extensions.
Users can add own extensions and keyword/syntax info.
New extensions can be advised to be aliases of an existing extension. Build treats as such.
Users can mod existing keyword info.
Mods are done via sub-options or directly (text editor .. um) to the text file holding preferences.
Included files use their own extension/type syntax scheme.[/list]