Allow square brackets after first character in shell fragment

corpus/maintainer.txt

@@ -8,3 +8,4 @@ Maintainer camden@ccheek.com
 
 (source_file
 	(maintainer_instruction))
+

grammar.js

@@ -310,7 +310,7 @@ module.exports = grammar({
 				),
 
 				shell_fragment: $ => repeat1(choice(
-					/[^\\\[\n#\s][^\\\[\n]*/,
+					/[^\\\[\n#\s][^\\\n]*/,
 					/\\[^\n]/,
 				)),
 

src/grammar.json

@@ -1314,7 +1314,7 @@
         "members": [
           {
             "type": "PATTERN",
-            "value": "[^\\\\\\[\\n#\\s][^\\\\\\[\\n]*"
+            "value": "[^\\\\\\[\\n#\\s][^\\\\\\n]*"
           },
           {
             "type": "PATTERN",

src/parser.c

@@ -2457,7 +2457,6 @@ static bool ts_lex(TSLexer *lexer, TSStateId state) {
       ACCEPT_TOKEN(aux_sym_shell_fragment_token1);
       if (lookahead != 0 &&
           lookahead != '\n' &&
-          lookahead != '[' &&
           lookahead != '\\') ADVANCE(225);
       END_STATE();
     case 226: