Content update from Nuritzi
[endlessm/eos-shell#4235]
Remove some stub pages

We ended up deciding to just link into some of our user doc pages
instead of rewriting any content in getting started
[endlessm/eos-shell#4235]
Add images to help pages

We are using some of the images from gnome-user-docs. I don't think
its worth the complexity and effort to copy every asset used in both
to this repo as well. Especially as they both install to the same
spot (/usr/share/help/gnome-help).

But user docs will need to be installed alongside this for all the
images to work
[endlessm/eos-shell#4235]
Add descriptions and alternate title text for some pages

Some help pages appear later in our help pages and not just on the
home page. In those later sections, they need to have a description
and sometimes alternate title text
[endlessm/eos-shell#4235]
Update pot file
[endlessm/eos-shell#4235]
Merge pull request #8 from endlessm/shell/4235

Shell/4235