Add "how to use" documentation

diff --git a/README.md b/README.md
index 0f6f097781a9d7efd47fe1d594d6ce4a9c070e82..ec4c50d5f995c68cf23c37daa97df065e7c8f4e4 100644 (file)
--- a/README.md
+++ b/README.md
@@ -5,6 +5,20 @@ This is a set of files I use for making 3D objects.
 It mostly consists of my own work, but occasionally I include other
 people's work if that other work has a suitable licence.
 
+# How to use
+
+To add to your project:
+
+```
+git subtree add -P diziet-utils https://salsa.debian.org/iwj/3d-utils.git main
+```
+
+To update to a new version:
+
+```
+git subtree pull -P diziet-utils https://salsa.debian.org/iwj/3d-utils.git main
+```
+
 # Licence
 
 Everything is GPLv3+ (or compatible).