message: docs(elements): move clarification about custom elements
  Moved clarification that "custom elements" are a subtype of Web Components to the first use of the term "custom elements"
  PR Close
diff: # Angular Elements Overview
  -_Angular elements_ are Angular components packaged as _custom elements_, a web standard for defining new HTML elements in a framework-agnostic way.
  +_Angular elements_ are Angular components packaged as _custom elements_ (also called Web Components), a web standard for defining new HTML elements in a framework-agnostic way.
  [Custom elements](https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements) are a Web Platform feature currently supported by Chrome, Firefox, Opera, and Safari, and available in other browsers through polyfills (see [Browser Support](#browser-support)).
  A custom element extends HTML by allowing you to define a tag whose content is created and controlled by JavaScript code.
  -The browser maintains a `CustomElementRegistry` of defined custom elements (also called Web Components), which maps an instantiable JavaScript class to an HTML tag.
  +The browser maintains a `CustomElementRegistry` of defined custom elements, which maps an instantiable JavaScript class to an HTML tag.
  The `@angular/elements` package exports a `createCustomElement()` API that provides a bridge from Angular's component interface and change detection functionality to the built-in DOM API.
  