docs: Adds information about changes when running in a development environment

README.md

@@ -39,6 +39,17 @@ To run Surveillance using docker, decide between development/testing or producti
 
 3. Visit `http://localhost:8081/` in a browser; you should see an interactive OpenStreetMap
 
+4. You can see most cameras on the map immediately; the `data_handler` background process continuously applies updates from OpenStreetMap which become visible after refrshing the page
+
+5. Appending `-f docker-compose.dev.yml` applies these changes:
+
+   - PHP won't supress any errors; to disable this, remove `return;` in `./web/www/sunders/config.php`
+
+   - Making changes in the `web` will immediately apply them to the running containers; try modifying `web/www/sunders/index.php`
+
+   - Making changes in the `data_handler` will immediately apply them to the running containers (try modifying `data_handler/utils/update_camera.sh`)
+
+   - The host has access to database files at `./mariadb`
 ### Production
 
 1. Close this repository
@@ -49,7 +60,7 @@ To run Surveillance using docker, decide between development/testing or producti
 
 3. Visit `http://localhost:8081/` in a browser to open the web interface
 
-4.
+4. You can see most cameras on the map immediately; the `data_handler` background process continuously applies updates from OpenStreetMap which become visible after refrshing the page
 
 ## Surveillance nodes