Compatibility with nvim-ts-rainbow

[kiryph]

I have raised the issue p00f/nvim-ts-rainbow#136 for the neovim plugin nvim-ts-rainbow.

However, the author has issues to support the filetype make.

The error encountered is Invalid Node Type: command_substitution.

The considered make source code is:

docs := $(addprefix $(OUTPUT_DIR), $(notdir $(graphs:%.graphml=%.$(FORMAT))))

clean:
	-$(RM) $(foreach ext, $(CLEAN_EXTS), $(docs:%.$(FORMAT)=%.$(ext)))

Can something be done on the side of the tree sitter grammar to remove this error?

[kiryph]

The issue has been resolved: the right node name was substitution_reference