Add reference .env on each push

[ozym4nd145]

Currently, the .env is automatically encrypted by git hook and pushed as .env.secret.
While this is good, it doesn't give user any idea about the content of original .env.

We should actually have a hook, that automatically censors the .env (for example, change value of each key to XXXXX) and then pushes this as .env.sample along with the commit.

This would eliminate the need to separately keep a list of environment variables updated and would help anyone understand the needed environment variables.