Update INSTALL.md to mention OpenSSL issue and other details

INSTALL.md

@@ -2,20 +2,51 @@ Vervis is still in early development. These instructions may be incomplete
 and/or slightly outdated. At the time of writing, you can get a running Vervis
 instance if you follow the steps below.
 
-Install Darcs, GHC 7.10.3 and a recent `stack` version.
+Check the version of OpenSSL installed on your system. For example:
 
-Download the Vervis repo:
+    $ apt show openssl
 
-    $ darcs clone http://hub.darcs.net/fr33domlover/vervis
+Currently Vervis is using a slightly old software configuration, and until I
+fix that, it doesn't build with OpenSSL 1.1 and needs the older 1.0 or 1.0.1
+version. If your distro has 1.1, see if you can grab 1.0 or 1.0.1 in some way,
+either through the distro package or by downloading OpenSSL manually from its
+website, or some alternative package manager such as GNU Guix.
+
+Install stack. To install stack, go to its website and follow the instructions.
+If you have some old version, such as one installed from FPComplete's old
+debian repo, you may need to upgrade it.
+
+Install Darcs. You can grab it from your distro, e.g.:
+
+    $ sudo apt install darcs
+
+If you're going to create a Git repository on Vervis, you'll need Git too, you
+can install it from a distro package too, e.g.:
+
+    $ sudo apt install git
+
+Clone the Vervis repo:
+
+    $ darcs clone https://dev.seek-together.space/s/fr33domlover/r/vervis
     $ cd vervis
 
+Install GHC. Unless you prefer to use a distro package or PPA or some other
+source, the easiest way is to install via stack:
+
+    $ stack setup
+
 Check in `stack.yaml` near the top which extra repos are required. At the time
 of writing, there are 4 of them (`hit-harder`, `hit-graph`, `hit-network` and
 `ssh`). Then clone them. For example:
 
     $ darcs clone http://hub.darcs.net/fr33domlover/ssh
 
-Update `stack.yaml` to specify that path in the `packages` section:
+Some of those extra repos are at `hub.darcs.net` and some at
+`dev.seek-together.space/s/fr33domlover/r`, I'm sorry I'm not just listing the
+URLs here. These things have been changing often, but once they stabilize I
+will update the docs, and also make releases of all these extra libraries.
+
+Update `stack.yaml` to specify that path in the `packages` section if needed:
 
     $ vim stack.yml
 
@@ -32,16 +63,21 @@ Create a new PostgreSQL user and a new database.
 
     $ #TODO take this from the vervis ticket I wrote...
 
-Update `stack.yaml` to specify correct database connection details.
+Update `config/settings.yml` to specify correct database connection details and
+other settings.
 
-    $ vim stack.yaml
+    $ vim config/settings.yml
 
 Build.
 
-    $ stack build --flag vervis:dev
+    $ stack build
 
 Run.
 
     $ stack exec vervis
 
-Browse to `http://localhost:3000` and have fun.
+Browse to `http://localhost:3000` and have fun!
+
+`yesod devel` is another way to run the application, useful for rapid
+development, but I haven't been using it and I'm not sure it works, possibly I
+broke something along the way. But feel free to try!