Kallithea internals overview

[Thomas De Schampheleire]

Hi,

What would be useful to me (and probably to other new contributors) is
a technical overview of Kallithea's internals.

Browsing the code as a newcomer only provides so much insight; it's
difficult to get a good overview of the different components and how
they fit together.

For example, there are
- templates
- controllers
- models
- ... ?

and then there are technologies like pylons, cellery, rabbitmq,
fontello ... and various javascript libraries like mergely, select2,
jquery and what not.

Even though I already know for some of them how they (more or less)
fit in the picture, a grand overview of all this would be a big help.
This could even be added in the documentation.

Thanks,
Thomas