Updated documentation and fixes for multiple DSIDs

More info will be added - just to keep track of added items for now.

• Added checklist for approvers in .gitlab/merge_request_templates/new_jO.md also in README (Closes #19 (closed))
• Updated instructions for how to upload new jO using the automatic script (Closes #18 (closed))
• Added git push -o ci.skip origin in automatic script to skip the pipelines when the branch is first created
• Pick up Frank's change for check_added_files
• Skip athena jobs for directories where there is no log.generate.short (Closes #17 (closed))
• Use Gen_tf instead of Generate_tf (Closes #16 (closed))
• Check that there are no explicit "MC15JobOptions/..." includes
• Change check_modified_files to fix #25 (closed)