[Aug 1] Better docs

[motdotla]

We've revamped dotenv and dotenv-vault's documentation pages.

It's here now: https://docs.dotenv.org

There's a solid Getting Started page now and better details and examples for the dotenv-vault commands.

Going forward you'll see how-to guides added and more getting started guides around the various dotenv-vault tools.

Enjoy and thank you for using dotenv and dotenv-vault.