Add more instructions to get auto-update for templates

Author: GuillaumeGomez

README.md

@@ -73,7 +73,10 @@ cargo run -- build add-essential-files
 # This starts the web server but does not build any crates.
 # It does not automatically run the migrations, so you need to do that manually.
 cargo run database migrate
-cargo run start-web-server
+# Start the web server. It doesn't automatically reload templates though!
+cargo run -- start-web-server
+# If you want the server to automatically reload templates if they are modified:
+cargo run -- start-web-server --reload-templates
 ```
 
 If you need to store big files in the repository's directory it's recommended to