Scheme: Improved boolean (#2316)

I noticed that scheme booleans also partially highlighted `#true`, so I fixed that.

components/prism-scheme.js

@@ -44,7 +44,7 @@ Prism.languages.scheme = {
 		pattern: /([\s()])(?:(?:#d(?:#[ei])?|#[ei](?:#d)?)?[+-]?(?:(?:\d*\.?\d+(?:[eE][+-]?\d+)?|\d+\/\d+)(?:[+-](?:\d*\.?\d+(?:[eE][+-]?\d+)?|\d+\/\d+)i)?|(?:\d*\.?\d+(?:[eE][+-]?\d+)?|\d+\/\d+)i)|(?:#[box](?:#[ei])?|#[ei](?:#[box])?)[+-]?(?:[\da-fA-F]+(?:\/[\da-fA-F]+)?(?:[+-][\da-fA-F]+(?:\/[\da-fA-F]+)?i)?|[\da-fA-F]+(?:\/[\da-fA-F]+)?i))(?=[\s()]|$)/,
 		lookbehind: true
 	},
-	'boolean': /#[tf]/,
+	'boolean': /#[ft](?=[()\s]|$)/,
 	'operator': {
 		pattern: /(\()(?:[-+*%\/]|[<>]=?|=>?)(?=\s|$)/,
 		lookbehind: true

tests/languages/scheme/boolean_feature.test

@@ -1,13 +1,19 @@
 #t
 #f
 
+; not a boolean
+#true
+
 ----------------------------------------------------
 
 [
 	["boolean", "#t"],
-	["boolean", "#f"]
+	["boolean", "#f"],
+
+	["comment", "; not a boolean"],
+	"\r\n#true"
 ]
 
 ----------------------------------------------------
 
-Checks for booleans.
+Checks for booleans.