fix: parse multi-word unquoted string values

grammar.js

@@ -62,9 +62,12 @@ module.exports = grammar({
 
     string: $ => choice(
       $._string,
-      $._literal_string
+      $._literal_string,
+      $._unquoted_string,
     ),
 
+    _unquoted_string: $ => alias(/[^\#\s\"\'\$]+(?:[ \t]+[^\#\s\"\'\$]+)+/, $.string_content),
+
     _literal_string: $ => seq(
       "'",
       optional(alias(/[^']+/, $.string_content)),

src/grammar.json

@@ -212,9 +212,22 @@
         {
           "type": "SYMBOL",
           "name": "_literal_string"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "_unquoted_string"
         }
       ]
     },
+    "_unquoted_string": {
+      "type": "ALIAS",
+      "content": {
+        "type": "PATTERN",
+        "value": "[^\\#\\s\\\"\\'\\$]+(?:[ \\t]+[^\\#\\s\\\"\\'\\$]+)+"
+      },
+      "named": true,
+      "value": "string_content"
+    },
     "_literal_string": {
       "type": "SEQ",
       "members": [

test/corpus/comments.txt

@@ -13,6 +13,8 @@ EMPTY_WITH_COMMENT_WHITESPACE =      # comment
 
 STRING_VALUE_WITH_COMMENT = 'string content'     # comment
 STRING_VALUE_WITH_COMMENT = "string"     # comment
+STRING_MULTIWORD_WITH_COMMENT = one   two   three      # comment
+SINGLE_WORD_WITH_COMMENT = singleword     # comment
 
 --------------------------------------------------------------------------------
 
@@ -36,5 +38,13 @@ STRING_VALUE_WITH_COMMENT = "string"     # comment
    key: (identifier)
    value: (string
         (string_content)))
+  (comment)
+  (assignment 
+   key: (identifier)
+   value: (string
+        (string_content)))
+  (comment)
+  (assignment 
+   key: (identifier)
+   value: (value))
   (comment))
-

test/corpus/string_values.txt

@@ -2,6 +2,11 @@
 String values
 ================================================================================
 
+key = multi word non    quoted string
+key = hyphenated-value another.value
+key = value with trailing spaces      
+key = singleword
+
 key = "quoted string"
 key = ""
 
@@ -11,6 +16,21 @@ key = ''
 --------------------------------------------------------------------------------
 
 (document
+ (assignment
+  (identifier)
+  (string
+   (string_content)))
+ (assignment
+  (identifier)
+  (string
+   (string_content)))
+ (assignment
+  (identifier)
+  (string
+   (string_content)))
+ (assignment
+  (identifier)
+  (value))
  (assignment
   (identifier)
   (string