Add global search across components, documentation, api #1157

As a developer, it is nearly impossible to quickly find what you are looking for on material.angular.io, without having to click into every link and scroll, then click.

Please provide a global search that returns results based on Feature, Component, API, etc, so that a user can quickly get to the documentation needed.

For a great example to model after, please see https://quasar.dev/ documentation.