homogenize community files across training materials

[avallecam]

the repos using the workbench with the latest reviews on them are:

• https://github.com/epiverse-trace/tutorials/
• https://github.com/epiverse-trace/git-rstudio-basics/

list:

• [ ] README
• [ ] CONTRIBUTING.md
• [ ] SUPPORT.md
• [ ] LICENSE.md
• [ ] CODE_OF_CONDUCT.md