erlang: highlight unary '#' as punctuation.bracket

The '#' character may either be interpreted as a map when used
like so:

    %% Example 1
    #{a => b}

Or as an operator which updates an existing map when the left-hand
side is an expression:

    %% Example 2
    MyMap#{a => b}

This commit changes the highlight to `punctuation.bracket` when used
as a character in a literal map (example 1) and keeps the `operator`
highlight when used for updating (example 2).

runtime/queries/erlang/highlights.scm

@@ -92,7 +92,7 @@
 
 (binary_operator operator: _ @operator)
 (unary_operator operator: _ @operator)
-["/" ":" "#" "->"] @operator
+["/" ":" "->"] @operator
 
 (tripledot) @comment.discard
 
@@ -123,6 +123,6 @@
 
 ; Punctuation
 ["," "." "-" ";"] @punctuation.delimiter
-["(" ")" "{" "}" "[" "]" "<<" ">>"] @punctuation.bracket
+["(" ")" "#" "{" "}" "[" "]" "<<" ">>"] @punctuation.bracket
 
 ; (ERROR) @error