build: refactoring sphinx build logic and changing approach to fabric use
build,minor: refactoring build file for pdfs, to be less obtuse.
build: moving the utils.py file and refactoring the way pdfs are generated.
minor: moving stale files
build: refactoring sphinx and image building
minor: fixing import
minor: fixing operation sequence for pdf builds and adding dependency to reduce sitemap related errors
minor edits to images
DOCS-1523 replica sets core toc
DOCS-1523: edits
DOCS-1501 edit images change font style light to regular