Add lots of docs, mostly best practices.

Start out on the visualisation docs.

Expand overview, remove federation as a feature we don't have that yet.

Switch example variable to follow naming scheme.
Comma after "For example" (http://english.stackexchange.com/questions/132359/any-exception-with-commas-before-and-after-for-example).

I think for now should spell them "push gateway" and "alert manager" (My feeling is that if we're using these like descriptive words in normal English, they should be spelled as two words and lower-case.), though I don't feel strongly at all about that. Main thing is that we standardize and make things consistent.