Add gitea-runner installation script and update READMEs

- Added new gitea-runner/install.sh script for deploying a Gitea Act
  Runner on Alpine LXC in Proxmox
- Updated main README with new script entry and adjusted formatting
- Added multi-OS support note to requirements
- Improved formatting in code examples with proper command separation
- Translated and enhanced gitea-runner/README.md with consistent
  terminology

README.md

@@ -2,24 +2,26 @@
 
 Public infrastructure deployment scripts designed to be executed directly via `curl | bash`.
 
-## Philosophy
+### Philosophy
 
 These scripts automate the deployment of personal infrastructure components. They are:
 
 - **Self-contained**: No external dependencies beyond standard Debian packages
 - **Idempotent-ish**: Safe to re-run (where possible)
 - **Curl-friendly**: Designed for one-liner deployment from a fresh server
+- **Multi-OS**: Supports Debian and Alpine-based deployments
 
-## Available Scripts
+### Available Scripts
 
 | Script | Description | Usage |
 |--------|-------------|-------|
-| [`proxy/install.sh`](proxy/) | Reverse proxy with Tailscale + Nginx Proxy Manager | `curl -fsSL https://gitea.arnodo.fr/Damien/infra-scripts/raw/branch/main/proxy/install.sh \| bash` |
-| [`netlab/install.sh`](netlab/) | Network lab with ContainerLab | `curl -fsSL https://gitea.arnodo.fr/Damien/infra-scripts/raw/branch/main/netlab/install.sh \| bash` |
-| [`seedbox/install.sh`](seedbox/) | ISO seedbox with Transmission + NFS | `NFS_SERVER=<nas> curl -fsSL https://gitea.arnodo.fr/Damien/infra-scripts/raw/branch/main/seedbox/install.sh \| bash` |
+| [`proxy/install.sh`](proxy/) | Reverse proxy with Tailscale + Nginx Proxy Manager | `curl -fsSL https://gitea.arnodo.fr/Damien/infra-scripts/raw/branch/main/proxy/install.sh` \| `bash` |
+| [`netlab/install.sh`](netlab/) | Network lab with ContainerLab | `curl -fsSL https://gitea.arnodo.fr/Damien/infra-scripts/raw/branch/main/netlab/install.sh` \| `bash` |
+| [`seedbox/install.sh`](seedbox/) | ISO seedbox with Transmission + NFS | `NFS_SERVER=<nas> curl -fsSL https://gitea.arnodo.fr/Damien/infra-scripts/raw/branch/main/seedbox/install.sh` \| `bash` |
+| [`gitea-runner/install.sh`](gitea-runner/) | Gitea Act Runner on Alpine LXC (Proxmox) | `bash -c "$(curl -fsSL https://gitea.arnodo.fr/Damien/infra-scripts/raw/branch/main/gitea-runner/install.sh)"` |
 
-## Requirements
+### Requirements
 
-- Fresh Debian 12/13 installation
-- User with sudo privileges (do not run as root)
+- Fresh Debian 12/13 installation (proxy, netlab, seedbox) or Proxmox VE host (gitea-runner)
+- User with sudo privileges (do not run as root) — except gitea-runner which runs as root on Proxmox
 - Internet access