Linux: Added install scripts for bash and nushell

Added two scripts to help users install ghostty before it's available
from a user's preferred package manager.

install_linux.nu

@@ -0,0 +1,26 @@
+#!/usr/bin/env nu
+
+# Check if running as root
+if ((id -u | into int) != 0) {
+    echo "Please run as root (sudo)"
+    exit 1
+}
+
+# Build and install (errors will automatically cause exit in nu)
+zig build -Doptimize=ReleaseFast --prefix /usr install
+
+# Create desktop entry
+$"[Desktop Entry]
+Version=1.0
+Type=Application
+Name=ghostty
+Comment=Ghostty is a terminal emulator that differentiates itself by being fast, feature-rich, and native.
+Exec=/usr/bin/ghostty
+Categories=Development;
+Terminal=false" | save --force /usr/share/applications/ghostty.desktop
+
+# Set proper permissions
+chmod 644 /usr/share/applications/ghostty.desktop
+
+# Update desktop database
+update-desktop-database /usr/share/applications

install_linux.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# Exit on any error
+set -e
+
+# Check if running as root
+if [ "$EUID" -ne 0 ]; then 
+    echo "Please run as root (sudo)"
+    exit 1
+fi
+
+# Build and install
+zig build -Doptimize=ReleaseFast --prefix /usr install
+
+# Create desktop entry
+cat > /usr/share/applications/ghostty.desktop << 'EOL'
+[Desktop Entry]
+Version=1.0
+Type=Application
+Name=ghostty
+Comment=Ghostty is a terminal emulator that differentiates itself by being fast, feature-rich, and native.
+Exec=/usr/bin/ghostty
+Categories=Development;
+Terminal=false
+EOL
+
+# Set perms
+chmod 644 /usr/share/applications/ghostty.desktop
+
+# Update desktop database
+update-desktop-database /usr/share/applications