installation instrucions update
Merge pull request #1561 from tiagojsag/install_docs

Installation instructions
Edited new architecture file for typos and readability
Updated PostAdmin example in getting started so it's called 'sonata.admin.post' instead of 'sonata.admin.tag', in line with the example in the architecture chapter
Edited updated dashboard chapter for typos and readability, ref #1524
Broke YML examples up into multiple lines so they're easier to read (I hope the "list of arrays" syntax is common enough for people to understand)
Updated SonataPropelAdminBundle hyperlink ref #1561
Merge pull request #1582 from caponica/docs-20130819

Docs 20130819