Small config. changes for improved UX/SEO results.

 - Site name
 - Description
 - Config definitions (enabled search, center lead setting etc.)

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Merge pull request #5194 from ostezer/mkdocs-small-seo-fixes

Small config. changes for improved UX/SEO results.