docs(troubleshooting): add inotify limits documentation and workaround

Add comprehensive troubleshooting documentation for inotify instance limit
errors that cause Jellyfin crashes in environments with many containers.

Changes:
- Add Troubleshooting section to README with inotify limits explanation
- Document proper solution: increase kernel limits via sysctl
- Provide workaround for managed clusters: DOTNET_USE_POLLING_FILE_WATCHER
- Add commented example in values.yaml for easy copy-paste
- Update Chart version from 2.5.0 to 2.5.1
- Add Artifact Hub changelog annotation

The proper solution is to increase inotify limits on Kubernetes nodes:
```bash
sysctl -w fs.inotify.max_user_instances=512
```

For managed Kubernetes where node access is restricted, users can use the
polling workaround (less efficient but functional):
```yaml
jellyfin:
  env:
    - name: DOTNET_USE_POLLING_FILE_WATCHER
      value: "1"
```

This addresses the crash issue mentioned in #64.

Fixes: #64

Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: Aleksei Sviridkin <f@lex.la>

charts/jellyfin/values.yaml

@@ -192,7 +192,10 @@ jellyfin:
   # -- Additional arguments for the entrypoint command.
   args: []
   # -- Additional environment variables for the container.
+  # Example: Workaround for inotify limits (see Troubleshooting section in README)
   env: []
+  # - name: DOTNET_USE_POLLING_FILE_WATCHER
+  #   value: "1"
 
 persistence:
   config: