initial work to make a mockup

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
The UX spec

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
dynamically load a /versions.html_fragment file so that all old versions get the complete dropdown list of versions to select

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
the build cache is too agressive, and I am regularly getting builds using an old version - forcing the issue

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Add more details so I have more of an over-view of what I need to
automate

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
avoid publishing to the root unless specified, so old version releases only goto their own dir

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Merge pull request #7151 from SvenDowideit/add-version-selection-ux

Add version selection ux to the Documentation.