Apply suggestions from code review

Co-authored-by: Mathias Bynens <[email protected]>

Author: nicolo-ribaudo

README.md

@@ -109,7 +109,7 @@ These options can be set to `false` or `'transform'`. When using `'transform'`,
 
   ```js
   rewritePattern('(?<name>.)\\k<name>', '', {
-    namedGroup: "transform"
+    namedGroup: 'transform'
   });
   // → '(.)\1'
   ```
@@ -143,7 +143,7 @@ NOTE: Currently regexpu doesn't support any ECMAScript proposal
 ### Caveats
 
 - [Lookbehind assertions](https://github.com/tc39/proposal-regexp-lookbehind) cannot be transformed to older syntax.
-- When using `namedGroups: 'transform'`, _regexpu-core_ only takes care of the _syntax_: you will still need a runtime wrapper around the regular expression to populate the `.groups` property of `RegExp.prototype.match()`'s result. If you are using _regexpu-core_ via Babel, it's handled automatically.
+- When using `namedGroups: 'transform'`, _regexpu-core_ only takes care of the _syntax_: you still need a runtime wrapper around the regular expression to populate the `.groups` property of `RegExp.prototype.match()`'s result. If you are using _regexpu-core_ via Babel, it's handled automatically.
 
 ## Author