Add more detailed installation instructions

Add example systemd service

docs/INSTALLATION.md

@@ -0,0 +1,35 @@
+## Installing Satyr
+A more detailed walkthrough.
+
+### System Dependencies
+Install ffmpeg and mysql through your distribution's package manager.
+See [this page](https://nodejs.org/en/download/package-manager/) for instructions on install node. Compatible versions are >=10. Nightly builds may fail to compile some of the native addons.
+
+### Installing Satyr
+Clone the repository and change to the directory
+```bash
+git clone https://gitlab.com/knotteye/satyr.git
+cd satyr
+```
+Install nodejs dependencies
+```bash
+npm install
+```
+Run the setup script to generate a config file and database setup.
+```bash
+npm run setup
+```
+Look over the generated config file in config/generated.toml, and move it to config/local.toml when you're satisfied.
+Run the setup script for the database.
+```bash
+sudo mysql
+source install/db_setup.sql;
+```
+Compile the code and start the server.
+```bash
+npm run build
+npm start
+```
+
+It is reccomended that you run Satyr behind a TLS terminating reverse proxy, like nginx.
+An example systemd service is provided at install/satyr.service. It assumes you've installed satyr into /opt/satyr, and created a satyr user with the home directory /var/lib/satyr for the purpose of running the service.