add link to ADA_Rstudio_connect GitHub repo

[chfoster]

Overview of changes

Add video and link to new repo on pulling data from Databricks into R studio

Checklist before requesting a review

• I have checked the contributing guidelines
• I have checked for and linked any relevant issues that this may resolve
• I have checked that these changes build locally
• I understand that if merged into main, these changes will be publicly available

[rmbielby]

Approved, but just a minor tweak in case someone comes to it out of context (e.g. in that world where most of us already have all moved to our data to databricks).