update(docs): Better docs for build_script.sh

I updated docs for `build_script.sh` and enhanced them a little bit so
they're now more comprehensive, have better examples of usage and
documentation of command line options.
update(docs): Better docs for setup.sh

Docs for setup.sh now contain more comprehensive CLI descriptions, usage
examples, and fewer typos :)
Rename dev reqs for RTD
fix(docs): update build/setup scripts examples
fix(docs): exec. shell scripts, directory listing

I added a few notifications about using executable scripts for
build_wheels.sh and setup.sh.

Setup.sh now contains new sections: directory listing (after GWM
installation) and almost empty troubleshooting.
Make bash script link ref to setup-script docs
build-script.rst: Fix grammar
Merge branch 'pbanaszkiewicz-fix/documentation_gsoc' into develop

* pbanaszkiewicz-fix/documentation_gsoc:
  build-script.rst: Fix grammar
  Make bash script link ref to setup-script docs
  fix(docs): exec. shell scripts, directory listing
  fix(docs): update build/setup scripts examples
  update(docs): Better docs for setup.sh
  update(docs): Better docs for build_script.sh