add Sencho

Thanks for taking the time to suggest an addition to awesome-sysadmin!

Please fill out information below (all fields are mandatory unless noted otherwise):

```yaml
name: Sencho
website_url: https://sencho.io
source_code_url: https://github.com/Studio-Saelix/sencho
description: Self-hosted Docker Compose management platform for single host or multi-node fleet . Great for small DevOps teams, platform engineers and homelabs.
licenses:
- AGPL-3.0
platforms:
- Docker
- TypeScript
tags:
- software-containers
- control-panels
- deployment-automation
```

To ensure your issue is dealt with swiftly, please check the following (check the boxes `[x]`):

- [x] Submit one item per issue. This eases reviewing and speeds up inclusion.
- [x] You have searched the repository for any relevant [issues](https://github.com/awesome-foss/awesome-sysadmin-data/issues) or [PRs](https://github.com/awesome-foss/awesome-sysadmin-data/pulls), including closed ones.
- [x] Any software you are adding is not already listed at any of [awesome-selfhosted](https://github.com/awesome-selfhosted/awesome-selfhosted), [dbdb.io](https://dbdb.io/browse).
- [x] Any software project you are adding to the list is actively maintained.
- [ ] Any software project you are adding was first released more than 12 months ago.
- [x] Any software project you are adding has working installation instructions.

The issue provides Sencho's name, URLs, description, license, platforms, and tags; start by inspecting the repository's machine-readable data structure and existing entries. Add the item in the matching format, then verify that its required fields and links follow the repository's conventions.

Written by the indexing model from the issue text.