collection: Prepare for release 2.0.0 and housekeeping

[marcelmamula]

Disclaimer

This activity is part of major redesign of all roles in preparation for 2.0 release. More details in #45

Changes

• Update all README documents and add missing documents for modules (They are slated to be removed in future, but better to have doc than not have).
• Remove deprecated shell modules. They can be re-implemented but to sap_libs as full Python modules, not unsupported Shell modules.
• Update linting rules and add github workflows like sap_install collection.
• Fix linting issues found after activating new rules
• Remove old playbook samples, outdated documents and unused .gitkeep files

[sean-freeman]

LGTM 👍 Ready for immediate release

[berndfinger]

LGTM!