Restructures the demo-app by no longer mixing up the `demo-app` name.
Currently the `demo-app` consists of two parts:
* The demo-app
* And the accessibility demos
As you can tell above, this is pretty much confusing because it's
technically just consisting of:
* Accessibility demos
* Library demos
This change cleans up the naming and makes sure that the modules are
structured in a best-practice way.
It's odd to have the `DemoAppModule` (*not the root module*) that
includes all library demos as a folder next to the actual demo
components.
This makes it extremely hard to convert the demo-app to Bazel because
we cannot target all `.ts` files through `glob` because it only matches
files inside of the same folder (or Bazel package).
In order to make it easy to run the demo-app with Bazel, and to just
clean it up, the folder structure should be as followed:
```
src/a11y-demo/
| ...
src/dev-app/
| ${DEMO_COMPONENT}
| ...
| BUILD.bazel
| index.html
| BUILD.bazel
```
* build: script to build demo-app for firebase
* Adds a new gulp task that can be used to build the devapp in "deploy"-mode. This allows us to deploy the demo-app on firebase.
Fixes#3857
* Add firebase deploy task
Paul Gschwendtner