Feature Request: Import from Uptime Kuma export file

**Is your feature request related to a problem? Please describe.**
No

**Describe the solution you'd like**
Like some other users, I'm considering moving over from Uptime Kuma (UK). For now I'm just adding a few monitors (instead all my 103). UK allows a bulk export as backup, so a natural feature (if indeed you want to soak up all the unhappy UK users) would be an Import feature on Peekaping from this export file. That would mean an UK user could spin up Peekaping + Notification service, export from UK, import into Peekaping, done. Instead I need to _manually_ add each monitor I currently have. This makes switching more effort, so I'll be "trialling" Peekaping for longer to check it meets all my needs before going through the "effort" of manually adding all monitors. If I could import it'd make moving over easier as I could 1:1 check features against all my 103 monitors.

**Describe alternatives you've considered**
As the UK backup feature is deprecated, maybe an export from the ./data/ directory instead?

**Additional context**
N/A

The issue requests an import feature for Uptime Kuma export files. First, examine the repository's structure for existing import/export logic, likely in a cmd or internal directory. Understand the Uptime Kuma export format by reviewing its documentation or sample data. Determine where monitor data is stored in Peekaping (database models or configuration files). Implement a parser for the UK format and map fields to Peekaping's monitor model. Test with a sample export file to ensure monitors are created correctly.

Rédigé par le modèle d'indexation à partir du texte de l'issue.