By default set to 'highlight'; set it to full path to highlight
executable if it is not installed on your web server's PATH.
Note that 'highlight' feature must be set for gitweb to actually
- use syntax hightlighting.
+ use syntax highlighting.
+
*NOTE*: if you want to add support for new file type (supported by
"highlight" but not used by gitweb), you need to modify `%highlight_ext`