Editing developer intro pages
Further page edits
Proofing fixes & style stuff
Merge pull request #223 from hflynn/rebased/develop/10212-fix

Editing developer intro pages (rebased onto develop)
Initial re-org of contribution section
Migrate VideoFormat... to internal docs
Move Development.txt to 'contributing'
Move UsingGit to using-git
Merge UsingGitFlow with UsingGit

This has become the very much shortened
"Branch Naming" section, which likely needs
to be lengthened and perhaps re-positioned.
Combine dev and jenkins into testing.txt
Merge *Standards into standards
Rename Logging
Move some of Process into standards
Move accept test to testing.txt
Remove Process.txt
Final renamings

 * No more files are in Development/
 * Build became build-system
 * ReleaseProcess became release-process
Minor improvements for the HTML look
Re-order CI sections
Fix 'contribute to'
Moving 'Git resource' to the bottom