There may be cases when it is required to have code highlighting with the Smart Mode off, or when the language you need is not supported.
For such cases, JetBrains Fleet provides the ability to add custom TextMate bundles.
Add a TextMate bundle
Locate the .fleet folder in your user home directory.
In .fleet, create the textmate folder, and place the required TextMate bundles there, for example:
After you restart JetBrains Fleet, it will pick up the provided bundles and add the highlighting for the respective file types.