Fix #1475 documentation with docma

[offtherailz]

Fix #1475. Add documentation using docma:

• gets markdown from docs dir
• gets jsdoc from reducers, actions, epics, components and plugins
• create a single page application to deploy inside mapstore2 directly
• Fixes Document existing plugins using docma #1300 documenting some plugins, together with actions, reducers, epics

[coveralls]

Coverage remained the same at 77.109% when pulling 5178896 on offtherailz:docma into c735782 on geosolutions-it:master.

[coveralls]

Coverage decreased (-0.1%) to 76.999% when pulling 5178896 on offtherailz:docma into c735782 on geosolutions-it:master.

[coveralls]

Coverage decreased (-0.05%) to 77.059% when pulling 534ceb6 on offtherailz:docma into c735782 on geosolutions-it:master.