how to document a page

[amitu]

We should be able to do this:

-- ps.page: sitemap Page
url: /-/sitemap/

Every FPM package contains `sitemap page`, which can be used by site admins
to organise/understand their site.

-- ps.query-parameter: Username
optional: true

This is the username of the person. 

-- ps.page-state: Non Logged In
src: $assets.files.pages.sitemap.png

Clicking on green button takes you to another.

-- ps.page-state: Logged in
src: $assets.files.pages.sitemap.png

-- ps.page-data:
lang: ftd

\-- foo:

-- ps.data: Foo

Foo is used for some reason.