Rename doc to getting-started for introductory docs

Signed-off-by: Pavlos Ratis <dastergon@gentoo.org>
enrich docs with more introductory notes

Signed-off-by: Pavlos Ratis <dastergon@gentoo.org>
slight improvements to README

Signed-off-by: Pavlos Ratis <dastergon@gentoo.org>
remove project name header from readme
remove extra whitespace
use symlinked doc for duplicated info

The getting-started doc was basically a duplicate of the readme, so just
use that directly.