README: Add installation instructions

README.md

@@ -6,6 +6,32 @@ Checks the official JSON files every once in a while (configurable in the config
 file) for changes and sends new warnings to registered users based on the
 coordinates the entered.
 
+## Install
+
+(tested on Linux Mint 20.2)
+
+1. Install dependencies
+
+       sudo apt install libsqlite3-mod-spatialite
+
+2. Install nina_xmpp
+
+       pip3 install git+https://github.com/jplitza/nina_xmpp.git
+
+   Alternatively with user only privileges:
+
+       pip3 install --user git+https://github.com/jplitza/nina_xmpp.git
+
+3. Configure config.yml
+
+       wget https://raw.githubusercontent.com/jplitza/nina_xmpp/master/config.sample.yml -O config.yml
+
+   Open config.yml in your favourite text editor and adapt to your needs, i.e. provide XMPP credentials and admin contact
+
+4. Run
+
+       nina_xmpp config.yml`
+
 ## Usage
 
 Chat with the JID specified in the config to register yourself for warnings: