Add complete installation scripts for easy deployment

- install_rdp_client_complete.sh: Full-featured installer with auto-detection
- install_rdp_client_https.sh: Simple HTTPS-based installer
- INSTALL_INSTRUCTIONS.md: One-line installation commands and documentation

Features:
- Auto-detects Linux distribution (apt, dnf, yum, zypper, pacman)
- Installs all system dependencies automatically
- Sets up Python virtual environment
- Creates desktop entry and launcher
- Supports both SSH and HTTPS repository access
- Includes uninstall option
- Comprehensive error handling and user feedback

INSTALL_INSTRUCTIONS.md

@@ -0,0 +1,60 @@
+# RDP Client - One-Line Installation Commands
+
+## For users with SSH access to the repository:
+
+```bash
+curl -fsSL https://gitea.egonetix.de/root/rdp_client/raw/branch/main/install_rdp_client_complete.sh | bash
+```
+
+## For users without SSH access (HTTPS version):
+
+```bash
+curl -fsSL https://gitea.egonetix.de/root/rdp_client/raw/branch/main/install_rdp_client_https.sh | bash
+```
+
+## Manual download and install:
+
+```bash
+# Download the complete installer
+wget https://gitea.egonetix.de/root/rdp_client/raw/branch/main/install_rdp_client_complete.sh
+chmod +x install_rdp_client_complete.sh
+./install_rdp_client_complete.sh
+```
+
+## What the installer does:
+
+1. **Detects your Linux distribution** and installs required packages:
+   - freerdp2-x11 (RDP client)
+   - python3, python3-pip, python3-tk
+   - git
+   - xrandr
+
+2. **Clones the repository** to `~/rdp-client`
+
+3. **Sets up Python virtual environment** with dependencies:
+   - cryptography (for credential encryption)
+
+4. **Creates desktop entry** and launcher script
+
+5. **Tests the installation** to ensure everything works
+
+## After installation:
+
+- Run from command line: `rdp-client`
+- Find in applications menu: "RDP Client"
+- Configuration stored in: `~/.config/rdp-client/`
+
+## Uninstall:
+
+```bash
+./install_rdp_client_complete.sh --uninstall
+```
+
+## Features included:
+
+✅ Multi-monitor support with intelligent selection  
+✅ Encrypted credential storage  
+✅ Professional GUI interface  
+✅ Connection profiles  
+✅ Advanced RDP options  
+✅ Automatic dependency management