I gave a brief introduction on Automatic Reports with RMarkdown at USCbiostats R Bootcamp for Scientific Computing 2020.
I attached my slides here.
The corresponding github repo: 
Youtube recording link: 
Related tweets:
Thank you George Vega Yon (https://t.co/EyFG7xbheD) for mobilizing our team (@kerenxuepi @malco_barrett @Emil_Hvitfeldt and others) to introduce R in 3 short seminars to our new students @uscphshttps://t.co/QpMXuAk01k via @YouTube
— USC Biostatistics (@USCBiostat) August 18, 2020