Update docs to contain mentioning of `SSD1681` and `WeAct`

[ss89]

Describe the problem you have/What new integration you would like I tend to browse the docs of esphome to decide on which components to buy for a certain project.

Not finding a component usually leads to me using a different one instead.

This time (due to only 3 epaper displays being visible on the docs preview pages) i digging a bit deeper and first searched for what displays are on the market and somewhat cheap available. I saw that the WeAct epaper displays are available, but not listed as compatible in the esphome docs. Then i searched through the issues and feature requests repo of esphome, just to see if someone requested a component for it yet and here we go: https://github.com/esphome/feature-requests/issues/2697

Since they seem to work as per @latonita, it would be great if they could be mentioned in the docs with the brands name that sells the hardware display component (WeAct) and also with the controllers name (SSD1681). This way everyone can easily see that they should work out-of-the-box.

Please describe your use case for this integration and alternatives you've tried:

see above section

Additional context

see above section