feat: add xcompose parser

queries/xcompose/highlights.scm

@@ -0,0 +1,20 @@
+(keysym) @constant
+
+((keysym) @constant.builtin
+ (#eq? @constant.builtin "Multi_key"))
+
+(text) @string
+
+"include" @include
+
+[ (octal) (hex) ] @number
+
+[ (modifier) "None" ] @type.qualifier
+
+[ "%L" "%H" "%S" ] @string.special
+
+[ "!" "~" ] @operator
+
+[ ":" "<" ">" "\"" ] @punctuation.delimiter
+
+(comment) @comment @spell

queries/xcompose/injections.scm

@@ -0,0 +1,2 @@
+((comment) @injection.content
+ (#set! injection.language "comment"))