Thumbnails and Links to YouTube Videos Not Always Being Shown

[seanwebbhalifax]

In readme files with links to YouTube videos the thumbnail/links are not always shown. If I refresh the readme file for Module 1 it randomly has some of the thumbnails and links, then refresh again and it shows other thumbnails and links.

To reproduce:

1. Go to https://github.com/DataTalksClub/data-engineering-zoomcamp/blob/main/01-docker-terraform/README.md
2. Scroll down the page and note the YouTube video thumbnail links - there should be 16 thumbnail links
3. There will probably be some missing
4. Refresh the page and the same or different thumbnail links will randomly be missing

I think there is a problem with either the markdown-videos api or camo.githubusercontent.com used by Github to cache the images. Maybe the service hosted at markdown-videos-api.jorgenkh.no (used to create the thumbnails of each YouTube video with a play button) is being overwhelmed and unable to create all of the thumbnails fast enough and there is some timeout issue with the Github cache.

I've noticed this in multiple browsers (Chrome, Edge) both at work and home on Windows 10 and iPhone.