[Feature] Use toml for configuration instaed of rc

[CupricReki]

The rofi-rbw.rc config file is non-standard and appears to use the same key,value format as toml. Toml is widely used and IDEs recognize the format.

Existing users would only need to rename their rofi-rbw.rc file to rofi-rbw.toml. You could easily keep backwards compatibility if you wanted.

[fdw]

Apart from some technical difficulties: What would be the advantage? The file is readable already and has no complicated content.