Add a note about core-js polyfilling (#12)

zloirock · mathiasbynens · commit b10e1591c8b9 · 2019-10-21T10:01:39.000+02:00
diff --git a/README.md b/README.md
@@ -124,3 +124,7 @@ function* tokenise(input) {
 ## Specification
 
 You can view the rendered spec [here](https://tc39.github.io/proposal-string-prototype-codepoints/).
+
+## Implementations
+
+- [Polyfill](https://github.com/zloirock/core-js#stringcodepoints)
