Feature: Vikunja service widget (#4118)

Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>

docs/widgets/services/index.md

@@ -128,6 +128,7 @@ You can also find a list of all available service widgets in the sidebar navigat
 - [Uptime Kuma](uptime-kuma.md)
 - [UptimeRobot](uptimerobot.md)
 - [UrBackup](urbackup.md)
+- [Vikunja](vikunja.md)
 - [Watchtower](watchtower.md)
 - [WGEasy](wgeasy.md)
 - [WhatsUpDocker](whatsupdocker.md)

docs/widgets/services/vikunja.md

@@ -0,0 +1,18 @@
+---
+title: Vikunja
+description: Vikunja Widget Configuration
+---
+
+Learn more about [Vikunja](https://vikunja.io).
+
+Allowed fields: `["projects", "tasks7d", "tasksOverdue", "tasksInProgress"]`.
+
+A list of the next 5 tasks ordered by due date is disabled by default, but can be enabled with the `enableTaskList` option.
+
+```yaml
+widget:
+  type: vikunja
+  url: http[s]://vikunja.host.or.ip[:port]
+  key: vikunjaapikey
+  enableTaskList: true # optional, defaults to false
+```