Even though this is an old post, I thought it would be helpful to mention an additional (partial and tangential) solution to this question on top of the very helpful workarounds that are already present in this thread.
At the time of writing (6 January 2021), GitHub has released a feature to upload .mp4
and .mov
files up to 10 MB in size to issues, pull requests and discussion comments (as shared here). This is a direct embed, instead of "linking" it to external URLs as what we usually do. It is already out of public beta. You can attach files by dragging and dropping, selecting or pasting them. A preview of GitHub's new notice can be seen here:
Perhaps, in the future, we can slowly nudge GitHub to eventually extend this native feature to READMEs as well.