Developer 675 Fuse Connectors Page

Here's a first look at the Fuse connectors page.

The connectors.js could be simplified, however, I tried to keep the structure similar to projects.js. This was for two reasons. Firstly, because it will make it easier to add filters and featured connectors later and secondly, because we may want to refactor projects.js and connectors.js due to their similarity.

Implemented:

* Pushes to the DCP based on the contents of the spreadsheet.
* Page generated by JS rather than statically at site build time. Makes it possible to implement filtering later.

Outstanding code changes:
* Decision to display the connectors page is hard-coded. Better to decide based on presence of connectors.adoc. 
* More-details link missing
* Target product filtering is hard-coded to 'fuse'

Fixes needed from Fuse team:

* Overview text needs providing
* Data tidying (in spreadsheet)
  * Many IDs are duplicated
  * Many short descriptions are too long
  * Long descriptions are missing
  * All connector code snippets missing


Fixes needed from Design team:
* Images need adding to static.jboss.org by the design team. This is contrary to the suggestion in the spreadsheet that they are configurable
* ~~Default connector image needed~~

Are we only going to have one section here? If so, why are we doing the level offset instead of just using a level 3 section header?