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/README.md

@@ -0,0 +1,33 @@
+# Git Hooks
+
+This directory contains Git hooks for the CV project.
+
+## Installation
+
+To install the hooks, run:
+
+```bash
+.githooks/install-hooks.sh
+```
+
+Or, configure Git to use this directory for hooks (Git 2.9+):
+
+```bash
+git config core.hooksPath .githooks
+```
+
+## Available Hooks
+
+### pre-commit
+
+Automatically generates `img/cv.webp` from `cv.pdf` when changes are committed.
+
+**Requirements:**
+- `pdftoppm` (from poppler-utils)
+- `magick` (ImageMagick)
+
+The hook will:
+1. Check if `cv.pdf` is being committed or has been modified
+2. Convert the first page of `cv.pdf` to a WebP image
+3. Save it as `img/cv.webp`
+4. Add the generated image to the commit