Add contact doc

Mix migrate from GCI student job done on the master branch
Quick fix small char problem
Add HOWTO a requested on the mailing list
Add converted (and slightly edited) documentation.

Based on the work of Shlok Inani as part of CCI.
Improve HOWTO.
Fix custom mount config chapter structure.
Document prelogin app type
Add ported user documentation (from CGI).
Fix build
test upload

will this work?
Update developer_manual/guidelines.rst

Moved to rST format
Base commit for 4 files

Code Reviews
Kanban
Styleguide
Translation
Base commit for 3 files

juniorjobs
roadmap
testing
Update developer_manual/juniorjobs.rst
Update developer_manual/testing.rst
Update developer_manual/roadmap.rst
App Development Placeholders

App Dev section placeholders created
Update access doc
Update developer_manual/getting_started.rst
Update developer_manual/filesystem.rst