First PR of the Year:D

The feature I am interested to continue working on was born👶🏻 from a bigger set of features that had the purpose of integrating other types of communication and media to Telescope. I think that it would be a great addition to Telescope and it will make it a more "complete" aggregator:D Currently, Telescope aggregates blog posts from several blog feeds.

The bigger set of features included things like incorporating videos to the timeline and showcasing live streams with an 'exclusive' chat. You can learn more about it in this GitHub issue #1026.

The feature I decided to implement was incorporating videos to the timeline. Aggregating videos is exactly the same as aggregating blog posts, since platforms like YouTube implemented an RSS feed that you can use to aggregate it your own content aggregator (although this seems to be something of a hidden feature, because I only found out about this thanks to help of my professor💡).

I broke up the feature implementation in two PRs, one that would address the front-end (#2596), and another that would address the back-end (#2581).

These PRs were created some time ago, and I decided to finish them after the holidays were done👩🏻‍💻🐱‍💻. For this week, I focused mainly on the back-end PR, as it introduced the changes to actually aggregate the videos. If the changes of the back-end PR are merged, it would make the front-end PR easier to actually run (you have to do some manual set-up to do a demo of the front-end PR).

For the back-end, I applied some changes that one of the reviewers requested, as well as adding a few tests to verify that it was working as intended.

As of the time of this writing, the PR is pending on review. Hopefully, it will be accepted after the review is done :D