README.rst (shown on github and also at the start of the html docs) shall
be like an elevator speech - convince readers in a very short time.
this is most important, everything else can come after we got the reader's interest.
include README into docs to avoid duplication.
also include CHANGES into docs.
add developer docs, move examples from tox.ini there
add separate support docs
remove glossary, most of what was there can be understood by an admin from context
move attic and compatibility note to the end
