zygospore-mode, a reversible C-x 1

Hello,

When zygospore-mode is on, `C-x 1` is reversible. 
For a gif example, see [the repository's README](https://github.com/LouisKottmann/zygospore-mode/tree/master).

I am the maintainer of this package. I tested it with

```
make recipes/zygospore-mode
M-x package-install-file working/zygospore-mode
M-x global-zygospore-mode
```
Then open several windows in a frame and press C-x 1 repeatedly

I also tagged a version for MELPA stable, and hope that works as well.

Have a nice evening!

Louis "Baboon" Kottmann