message: docs: update ECMAScript info
diff: @@ -346,13 +346,13 @@ elements and their children.
  The [official JavaScript language specification](https://en.wikipedia.org/wiki/ECMAScript).
  The latest approved version of JavaScript is
  -[ECMAScript 2016](http://www.ecma-international.org/ecma-262/7.0/)
  -(also known as "ES2016" or "ES7"). Many Angular developers write their applications
  -in ES7 or a dialect that strives to be
  +[ECMAScript 2017](http://www.ecma-international.org/ecma-262/8.0/)
  +(also known as "ES2017" or "ES8"). Many Angular developers write their applications
  +in ES8 or a dialect that strives to be
  compatible with it, such as [TypeScript](guide/glossary#typescript).
  Most modern browsers only support the much older "ECMAScript 5" (also known as "ES5") standard.
  -Applications written in ES2016, ES2015, or one of their dialects must be [transpiled](guide/glossary#transpile)
  +Applications written in ES2017, ES2016, ES2015, or one of their dialects must be [transpiled](guide/glossary#transpile)
  to ES5 JavaScript.
  Angular developers can write in ES5 directly.
  