fix(ruby) fixed typo (#3259)

src/languages/ruby.js

@@ -252,7 +252,7 @@ export default function(hljs) {
     },
     NUMBER,
     {
-      // negative-look forward attemps to prevent false matches like:
+      // negative-look forward attempts to prevent false matches like:
       // @ident@ or $ident$ that might indicate this is not ruby at all
       className: "variable",
       begin: '(\\$\\W)|((\\$|@@?)(\\w+))(?=[^@$?])' + `(?![A-Za-z])(?![@$?'])`