[Nanobox] Update Nanobox Guide

- Be a little clearer about what's going on at each step.
- Give more detailed update instructions (and be smarter about selecting the "latest" tag).
- Mention the `VAPID_*_KEY` variables.

Running-Mastodon/Nanobox-Guide.md

@@ -11,29 +11,39 @@ Development
 
 You will need Nanobox installed, along with Docker if you're on Linux (Windows
 and macOS can use Docker Native, but the bundled VirtualBox is more performant
-while the Docker team works out some filesystem speed issues). The process is
-simple - clone the repo, set a few variables with `nanobox evar add local
-{VARIABLE}={value}` (see below on which ones need to be set), and run `nanobox
-run` to get to a console. It will take some time to build your local dev
-environment, but once it's done, simply set up the DB using `bundle exec rake
-db:setup` as normal, and you're off.
+while the Docker team works out some filesystem speed issues). Once Nanobox is
+installed, the process is simple - clone the Mastodon repo, set a few variables
+with `nanobox evar add local {VARIABLE}={value}` (see below on which ones need
+to be set), and run `nanobox run` to get to a console. It will take some time to
+build your local dev environment, but once it's done, simply set up the DB using
+`bundle exec rake db:setup` as normal, and you're off.
 
 Production
 ----------
 
-To deploy, you'll need to create an application in [your Nanobox dashboard](https://dashboard.nanobox.io/apps)
-(which requires a [Nanobox.io](https://dashboard.nanobox.io/users/register)
-account), clone the repo (if you haven't already set up the local development
-environment), set the new app as your deploy target with `nanobox remote add
-{app-name}`, set up the variables below using either `nanobox evar add
-{VARIABLE}={value}` or the app's dashboard, and then run `nanobox deploy`.
+To deploy, you'll need to create an application in [your Nanobox
+dashboard](https://dashboard.nanobox.io/apps) (which requires a _free_
+[Nanobox.io](https://dashboard.nanobox.io/users/register) account), clone the
+Mastodon repo (if you haven't already set up the local development environment),
+set the new app as your deploy target with `nanobox remote add {app-name}`, set
+up the variables below using either `nanobox evar add {VARIABLE}={value}` or the
+app's dashboard, and then run `nanobox deploy`. It will take a while to build
+everything for deployment the first time, but the process handles itself.
 
 Updating
 --------
 
-To update, simply grab the latest tagged version with `git fetch && git checkout
-$(git tag | tail -n 1)`, then re-run `nanobox deploy` - Nanobox automatically
-handles the rest.
+To update in production, simply grab the latest tagged version with `git fetch &&
+git checkout $(git tag -l | grep -v 'rc[0-9]*$' | sort -V | tail -n 1)`, then
+re-run `nanobox deploy` - Nanobox automatically handles the rest. Updates should
+be much faster than the initial deploy, since the build should be cached on your
+own computer, and only changes are sent to the server itself. Either way, you
+shouldn't see any downtime while the update process runs.
+
+For development, grab the latest tagged version using the instructions above,
+then use a `nanobox run` console to perform all the upgrade steps in the Release
+Notes (except for installing dependencies - the `boxfile.yml` is updated as
+needed to pull those in automatically).
 
 Environment Variables
 ---------------------
@@ -55,6 +65,11 @@ variables:
 -   `OTP_SECRET` - set to a random string of characters; you can use `nanobox
     run bundle exec rake secret` to generate one
 
+-   `VAPID_PUBLIC_KEY` - generated by running `nanobox run bundle exec rake
+    mastodon:webpush:generate_vapid_key`
+
+-   `VAPID_PRIVATE_KEY` - generated at the same time as `VAPID_PUBLIC_KEY`
+
 You can also set some optional values, which should override the defaults in
 `.env.nanobox`: