Explain how to clone the right branch

diff --git a/README.md b/README.md
index f148af0976fc4e9c3f7ea56aa9858f6cf7fd6fc5..b15613ede4b17834bda74a5ebc6c9dc45d0d7742 100644 (file)
--- a/README.md
+++ b/README.md
@@ -14,3 +14,9 @@ web sites. There are a number of branches:
 * **theme-2009** theme for [2009.stateofthemap.org](https://2009.stateofthemap.org/)
 * **theme-2008** theme for [2008.stateofthemap.org](https://2008.stateofthemap.org/)
 * **theme-2007** theme for [2007.stateofthemap.org](https://2007.stateofthemap.org/)
+
+To clone this repository, use
+```sh
+git clone --single-branch --branch <branch> https://github.com/openstreetmap/stateofthemap.git
+```
+Replace `<branch>` with the name of the branch you want to clone.