feat: highlight destructuring parameters in function declarations

Closes #40

Author: nkrkv

queries/highlights.scm

@@ -77,6 +77,12 @@
 ; single parameter with no parens
 (function parameter: (value_identifier) @parameter)
 
+; first-level descructuring (required for nvim-tree-sitter as it only matches direct
+; children and the above patterns do not match destructuring patterns in NeoVim)
+(parameter (tuple_pattern (tuple_item_pattern (value_identifier) @parameter)))
+(parameter (array_pattern (value_identifier) @parameter))
+(parameter (record_pattern (value_identifier) @parameter))
+
 ; Meta
 ;-----
 

test/highlight/functions.res

@@ -2,6 +2,12 @@ let inc = n => n + 1
 //        ^ parameter
 //          ^ punctuation.special
 
+let fn = (a, (b, c), {d, e}, [f, g]) => a + b + c + d + e + f + g
+//        ^ parameter
+//            ^ parameter
+//                    ^ parameter
+//                            ^ parameter
+
 let uncurry = (. u, .x) => (u, x)
 //             ^ operator
 //                  ^ operator