UPDATE: real way
In Coda, open "Preferences", go to the "Editor", at the bottom, add a custom syntax mode.
According to this manual:
- Right click on
Coda.appin /Applicationsand selectShow Package Contents - Switch to
Contents/Resources/Modes/HTML.mode/Contents/Resources - Open ModeSettings.xml
<extension>ss</extension> .
(, SilverStripe.mode) ~/Library/Application Support/Coda/Modes
HTML.mode ~/Library/Application Support/Coda/Modes, , .
( /Library/Application Support/Coda/Modes .)