rc troff: Highlight *ROFF files

Fixes #2508

rc/extra/troff.kak

@@ -0,0 +1,29 @@
+# Detection
+# ‾‾‾‾‾‾‾‾‾
+
+hook global BufCreate .*\.\d+ %{
+    set-option buffer filetype troff
+}
+
+# Highlighters
+# ‾‾‾‾‾‾‾‾‾‾‾‾
+
+add-highlighter shared/troff group
+add-highlighter shared/troff/ regex '\\f[A-Z]' 0:attribute
+add-highlighter shared/troff/ regex '\\fB(.+?)\\f[A-Z]' 1:+b
+add-highlighter shared/troff/ regex '\\fI(.+?)\\f[A-Z]' 1:+i
+
+add-highlighter shared/troff/ regex '^\.[a-zA-Z]{1,2}\b' 0:meta
+add-highlighter shared/troff/ regex '^\.TH\s+[^\n]+' 0:title
+add-highlighter shared/troff/ regex '^\.SH\s+[^\n]+' 0:header
+add-highlighter shared/troff/ regex '^\.IR\s+(\S+)' 1:+i
+add-highlighter shared/troff/ regex '^\.BR\s+(\S+)' 1:+b
+add-highlighter shared/troff/ regex '^\.I\s+([^\n]+)' 1:+i
+add-highlighter shared/troff/ regex '^\.B\s+([^\n]+)' 1:+b
+
+# Initialization
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+
+hook -group troff-highlight global WinSetOption filetype=troff %{ add-highlighter window/troff ref troff }
+
+hook -group troff-highlight global WinSetOption filetype=(?!troff).* %{ remove-highlighter window/troff }