Request for FIRRTL language support

[tymcauley]

Language
FIRRTL: Flexible Intermediate Representation for RTL. This is an Intermediate Representation (IR) for digital circuit design.

Additional resources
Specification: https://github.com/chipsalliance/firrtl-spec
You can find compiled PDFs of the specification on the Releases page.

The specification itself contains KDE XML to define syntax highlighting for the spec's pandoc flow, which gives syntax highlighting for firrtl code blocks in the spec's PDF: https://github.com/chipsalliance/firrtl-spec/blob/main/include/firrtl.xml

There are a few other syntax highlighting resources for FIRRTL (emacs, vim, sublime text), but those aren't as well maintained as the KDE XML in the specification.