F#: fix keywords containing exclamation mark

components/prism-fsharp.js

@@ -9,7 +9,7 @@ Prism.languages.fsharp = Prism.languages.extend('clike', {
 			lookbehind: true
 		}
 	],
-	'keyword': /\b(abstract|and|as|assert|base|begin|class|default|delegate|do|done|downcast|downto|elif|else|end|exception|extern|false|finally|for|fun|function|global|if|in|inherit|inline|interface|internal|lazy|let|let!|match|member|module|mutable|namespace|new|not|null|of|open|or|override|private|public|rec|return|return!|select|static|struct|then|to|true|try|type|upcast|use|use!|val|void|when|while|with|yield|yield!|asr|land|lor|lsl|lsr|lxor|mod|sig|atomic|break|checked|component|const|constraint|constructor|continue|eager|event|external|fixed|functor|include|method|mixin|object|parallel|process|protected|pure|sealed|tailcall|trait|virtual|volatile)\b/,
+	'keyword': /\b(?:let|return|use|yield)(?:!\B|\b)|\b(abstract|and|as|assert|base|begin|class|default|delegate|do|done|downcast|downto|elif|else|end|exception|extern|false|finally|for|fun|function|global|if|in|inherit|inline|interface|internal|lazy|match|member|module|mutable|namespace|new|not|null|of|open|or|override|private|public|rec|select|static|struct|then|to|true|try|type|upcast|val|void|when|while|with|asr|land|lor|lsl|lsr|lxor|mod|sig|atomic|break|checked|component|const|constraint|constructor|continue|eager|event|external|fixed|functor|include|method|mixin|object|parallel|process|protected|pure|sealed|tailcall|trait|virtual|volatile)\b/,
 	'string': /@?("""|"|')((\\|\n)?.)*?\1B?/,
 	'preprocessor': /^\s*#.*/m,
 	'number': [