Initial commit: RRF and RSF demos

[erikhatcher]

@ajosh0504 - how's this look? Article link pointer will be adjusted when published soon.

[ajosh0504]

@erikhatcher Generally looks good. Some comments:

• Proofread the title and any markdown in the notebook. Eg: Notebook title says "Demostration"
• Run the pre-commit checks and make sure they pass before merging the notebook into main. Instructions on how to run the checks are here.

Let's merge this PR once the article is live and the link to it has been updated!

[erikhatcher]

@ajosh0504 Thanks and done! Note that pre-commit is flagging files that I didn't touch. The article is likely to be published today, and the pointer to it is an indirection through mdb.link - so let's commit this when it's ready and I can adjust the pointer when the article is published (likely around the same time).