Provide more detailed setup instructions

README.md

@@ -2,6 +2,26 @@
 
 This is scratching a weird itch that started when I saw my friends mostly online.
 
+## What is happening?!
+
+The project is built via [shadow-cljs](https://shadow-cljs.github.io/docs/UsersGuide.html).
+You can run a dev build like so:
+
+``` sh
+npx shadow-cljs server :app
+```
+
+This starts a web server at localhost:8080 and also starts an nRPL server that you can connect to in your editor 
+
+Similarly, a production-optimized app can be generated via
+
+``` sh
+npx shadow-cljs release :app
+```
+
+The server component has to be started separately.
+You probably want to do this from within your editor while developing (see below).
+
 ## Important paths
 
 * `src/heyarne/all_my_friends/server.clj`: Contains a simple HTTP server that serves static files and has a handler for uploads