New words on homepage
Add new about page

- Add new navigation
- Link to new /performance/about resource
- Skeleton HTML for Henry to put stuff in
Fix typo in routing
Update navigation links
Add Rosalie's text for the About page
Add statement about personally identifiable data
Use en-dash
Treating Excel as a noun
Minor style tweak

This is consistent with the style guide usage guidelines.
Trailing spaces
Remove unnecessary object extend
Added pdfs for prototypes section
Add Rosalie's text for the About page
Added links to Major Projects Authority dashboard prototypes pdf and Policy dashboards prototype pdf.
Make about page section width device specific

Also use a Sass calculation for it.
Merge pull request #572 from alphagov/feature/prototypes-pdf-links

Feature/prototypes pdf links
Merge pull request #569 from alphagov/rosalie-words

Add new about page and navigation
Pass controller maps into stagecraft api client

So that the client and server side can use independent controller mappings, and provide different code paths
Split html with newlines for easier debugging
Reorder arguments for tempalte context, so that the defaults do not override the module specifics