**Is your feature request related to a problem? Please describe.** Syntax highlighting doesn't turn of when I open a file with dts extension
**Describe the solution you'd like** Geany to pick C-like source highlighting
**Describe alternatives you've considered**
**Additional context** https://www.kernel.org/doc/Documentation/devicetree/booting-without-of.txt:1... format of the .dts "source" file is "C" like, supports C and C++