Tweak Vagrant info in README

README.md

@@ -139,14 +139,13 @@ Running `vagrant up` for the first time will run provisioning, which will:
 - Create a new VirtualBox virtual machine from that image
 - Run the provisioning script (located inside the Vagrantfile), which installs the system packages, Ruby gems, and JS modules required for Mastodon
 
-Once this has completed, the virtual machine will start a rails process. You can then access your development site at http://mastodon.dev (or at http://localhost:3000 if you haven't installed vagrants-hostupdater). Any changes you make should be reflected on the server instantly.
+Once this has completed, the virtual machine will start a rails process. You can then access your development site at http://mastodon.dev (or at http://localhost:3000 if you haven't installed vagrants-hostupdater). Any changes you make should be reflected on the server instantly. To set environment variables, copy `.env.production.sample` to `.env.vagrant` and make changes as required.
 
-When you are finished with your session, run `vagrant halt` to stop the VM. Next time, running `vagrant up` should boot the VM, and skip provsioning.
+When you are finished with your session, run `vagrant halt` to stop the VM. Next time, running `vagrant up` should boot the VM, and skip provisioning.
 
 If you no longer need your environment, or if things have gone terribly wrong, running `vagrant destroy` will delete the virtual machine (after which, running `vagrant up` will create a new one, and run provisioning).
 
 
-
 ## Contributing
 
 You can open issues for bugs you've found or features you think are missing. You can also submit pull requests to this repository. This section may be updated with more details in the future.