Continuosly deploy the website

To be implemented after #7 

Deploy it using GitHub pages and Hercules CI. [Here](https://github.com/mlabs-haskell/lambda-buffers/blob/92045d77ce7da3a5ba9b80c195a05d305a0c28e1/hercules-ci.nix#L21) how this was done for [lambda-buffers website](https://mlabs-haskell.github.io/lambda-buffers/).