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/README.md.gotmpl

@@ -85,3 +85,44 @@ extraVolumeMounts:
   - name: hwa
     mountPath: /dev/dri
 ```
+
+## Troubleshooting
+
+### inotify Instance Limit Reached
+
+**Problem:** Jellyfin crashes with error:
+```
+System.IO.IOException: The configured user limit (128) on the number of inotify instances has been reached
+```
+
+**Root cause:** The Linux kernel has a limit on inotify instances (file system watchers) per user. Jellyfin uses inotify to monitor media libraries for changes.
+
+**Proper solution (recommended):**
+
+Increase the inotify limit on the Kubernetes nodes:
+
+```bash
+# Temporary (until reboot)
+sysctl -w fs.inotify.max_user_instances=512
+
+# Permanent
+echo "fs.inotify.max_user_instances=512" >> /etc/sysctl.conf
+sysctl -p
+```
+
+Recommended values:
+- `fs.inotify.max_user_instances`: 512 or higher
+- `fs.inotify.max_user_watches`: 524288 or higher (if you have large media libraries)
+
+**Workaround (if you cannot modify host settings):**
+
+If you're running on a managed Kubernetes cluster where you cannot modify node-level settings, you can force Jellyfin to use polling instead of inotify. **Note: This is less efficient and may increase CPU usage and delay change detection.**
+
+```yaml
+jellyfin:
+  env:
+    - name: DOTNET_USE_POLLING_FILE_WATCHER
+      value: "1"
+```
+
+This workaround disables inotify file watching in favor of periodic polling, which doesn't require inotify instances but is less efficient.