move the documentation to markdown

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: )
Merge pull request #5206 from SvenDowideit/stage-markdown

move the documentation to markdown
move the documentation to markdown

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
now, with shiney markdown

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
Merge pull request #5219 from dotcloud/master-doc-markdown

now, with shiney markdown
Changed heading colors and some alignments (no longer center and justification in left column)

Docker-DCO-1.1-Signed-off-by: Thatcher Peskens <thatcher@docker.com> (github: dhrp)
Merge pull request #5224 from dhrp/tp-titles-colors

Changed heading colors and some alignments (no longer center and justification in left column)
Add missing "ps" requirement to PACKAGERS.md

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)