INSTALL.md: Move configuration to after stack build

The config file isn't parsed during build time anymore, so the app can be built
without it.

INSTALL.md

@@ -54,13 +54,10 @@ Clone the Vervis repo:
 
 Clone dependency libraries:
 
+    $ chmod u+x update-deps.sh
     $ ./update-deps.sh
 
-# (5) Configuration and database
-
-Generate a new SSH key with a blank password:
-
-    $ ssh-keygen -t rsa -f config/ssh-host-key
+# (5) Database
 
 Install PostgreSQL. You'll need the server and the client library development
 files. Note that PostgreSQL needs to be at least version 9.5.
@@ -85,30 +82,31 @@ Create a PostgreSQL database:
 
     $ createdb --encoding=UTF8 --owner=vervis vervis
 
+# (6) Build Vervis
+
+If you're building for a production deployment, set the `dev` flag to false in
+`stack.yaml`:
+
+    flags:
+      vervis:
+        dev: false
+
+Build. This will also automatically install the GHC Haskell compiler.
+
+    $ stack build
+
+# (7) Configuration
+
+Generate a new SSH key with a blank password:
+
+    $ ssh-keygen -t rsa -f config/ssh-host-key
+
 Update the settings to specify correct database connection details and other
 settings.
 
     $ cp config/settings-default.yaml config/settings.yml
     $ vim config/settings.yml
 
-# (6) GHC Haskell compiler
-
-`stack` can automatically install the correct GHC version for you, in an
-isolated location that doesn't conflict with any system packages. Unless you
-have a specific reason to get GHC in some other way, getting it through `stack`
-is recommended.
-
-If you'd like to install GHC manually (from a distro package, from a PPA,
-etc.), this is the time to do so. And I trust you to arrange things such that
-`stack` uses your manually downloaded GHC. Otherwise, simply proceed to the
-next step.
-
-# (7) Build Vervis
-
-Build. This will also automatically install GHC.
-
-    $ stack build
-
 # (8) Development and deployment
 
 To update your local clone of Vervis, run: