Improved troubleshooting

Author: mblaschke

documentation/TROUBLESHOOTING.md

@@ -2,13 +2,26 @@
 
 # Troubleshooting
 
-## Startup or (docker) linking errors
+## Startup or (docker) linking errors (safe reset)
 
-If you got any startup issues you can try to rebuild `main` and `web` containers:
+If you got any startup issues you can try to rebuild `main` and `web` containers.
+You won't lose any data with this way - it's a safe reset.
 
 ```bash
 docker-compose stop
 docker-compose rm --force main web
 docker-compose build --no-cache main web
 docker-compose up -d
 ```
+
+## Complete reset
+
+Reset all containers, delete all data (`mysql`, `solr` ..) but not your project files in `code/`!
+
+```bash
+docker-compose stop
+docker-compose rm --force
+docker-compose build --no-cache
+docker-compose up -d
+```
+