1. Introduce a new key in magnolia.properties file pointing to the content-type directory.
2. Load all files in that directory during content-types' module startup-phase
3. Create workspace and register nodetypes for the defined content-type.

Minimal requirement for now is to have the name and the namespace of the content-type read from the content-type file.

Example listing of the directory:

$ tree content-types/
content-types/
├── contact.ctd
├── event.ctd
└── my_file.ctd

For now we leave the files under the root-type directory and the filename is arbitrary. I don't want the namespace (e.g. 'mgnl') to be extracted from the filename.

$ cat contact.ctd
namspace 'mgnl'
entity 'contact'