Add tracked Git hooks and refactor timeline arrows

- Add .githooks directory with pre-commit hook for cv.webp generation
- Create installation script for hooks setup
- Add documentation for hooks usage
- Refactor timeline arrows into reusable commands (\timelinearrow and \timelinearrowcontinue)
- Simplify arrow usage by only requiring length parameter

.githooks/install-hooks.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+# Install git hooks from .githooks directory
+
+HOOKS_DIR=".githooks"
+GIT_HOOKS_DIR=".git/hooks"
+
+# Ensure .git/hooks directory exists
+if [ ! -d "$GIT_HOOKS_DIR" ]; then
+    echo "Error: .git/hooks directory not found. Are you in a git repository?"
+    exit 1
+fi
+
+# Copy all hooks from .githooks to .git/hooks
+for hook in "$HOOKS_DIR"/*; do
+    # Skip this installation script
+    if [ "$(basename "$hook")" = "install-hooks.sh" ] || [ "$(basename "$hook")" = "README.md" ]; then
+        continue
+    fi
+
+    if [ -f "$hook" ]; then
+        hook_name=$(basename "$hook")
+        echo "Installing $hook_name..."
+        cp "$hook" "$GIT_HOOKS_DIR/$hook_name"
+        chmod +x "$GIT_HOOKS_DIR/$hook_name"
+        echo "✓ $hook_name installed"
+    fi
+done
+
+echo ""
+echo "All hooks installed successfully!"