Docs: Move name explanation from README to docs

Lets keep the README simple and with useful data.
README: Remove note saying amaGama is a prototype

It has been working for years, despite there are no releases.
README: Rewrite and reduce the text to improve readability

The README should be short. We already have the docs for more extensive
explanations.
Cleanup and fix the template
Rearrange views code

Will ease further cleanups.
Add FIXME
Avoid having a view that choses which code to call
Remove other view that choses which code to call

There is a remaining view, but still not sure how to drop it.
Add setting to control if the web UI is enabled or not
Split remaining view that choses which code to call

This will ease enabling or not the data altering API.
Disable data altering API by default

Some deployments (possibly most of them) won't use this part of the API,
which is in fact most of the API, so disabling it by default might help
quickly deploy with minimum changes.

A setting is used to control if it is enabled or not, so it can be enabled
again if necessary.

Having two separate blueprints for the API makes much more easier to disable
part of the API.
Minor blueprint related changes

These changes will ease moving the views to views/
Tidy up: Move views to views/

Lets use an app organization closer to the one recommended for Flask apps.