On a not-so-completely unrelated note, if you didn't know on GitHub READMEs you can do things like

  ![img-text](assets//myimg_dark.png#gh-dark-mode-only)
  ![img-text](assets/myimg_light.png#gh-light-mode-only)

To automatically display the light or dark version of images depending on their gh theme (works html style too)

I'm also fond of

  <p align="center">
     ....
  </p>

Which I notice you do :), but did you know you could also do it to tables and center the caption?

  <table align="center">
    <tr>
      <td>
        <img width=800px src="https://user-images.githubusercontent.com/52205/87230973-412eb900-c381-11ea-8aec-cc200290bd1b.png" alt="image" />
        <br>
        <p align="center"><sub>delta with <code>side-by-side</code> and <code>line-numbers</code> activated</sub></p>
      </td>
    </tr>
  </table>

This isn't really a critique or anything, it is that I appreciate that you took the time to make things look pretty and it seems like you'd be interested in this kind of stuff

Also to others, this even works in issues and elsewhere. I find this stuff really helpful when writing issues