docs: update README

README.md

@@ -1,2 +1,15 @@
 # static.ubuntu-mate.org
-Video assets 📼
+
+- Video assets 📼
+
+## Git setup
+
+After creating this repo [LFS was enabled](https://github.com/git-lfs/git-lfs?tab=readme-ov-file#example-usage) via:
+
+```shell
+git lfs track "*.mp4"
+git lfs track "*.webm"
+git lfs track "*.webp"
+git add .gitattributes
+git commit -m "chore: track video files using LFS"
+```