[feature request] syntax highlighting for fish shell scripts

[WayfarerCodes]

fish is a pretty popular shell at this point and I personally make heavy use of it on my system. However, it's missing from FeatherPad's selection of syntax highlighting options, leaving fish shell scripts with the default lack of it. Adding highlighting for it would benefit everyone who uses it and this application.

[tsujan]

As a lightweight code editor that includes its syntax highlighting code (unlike most apps that depend on external libraries), there's a limit to the syntaxes it supports. As mentioned in README, common programming languages are supported. I'm afraid fish isn't one of them.