add a license

1 files changed, 2 insertions, 0 deletions

diff --git a/index.md b/index.md
index 9fc8512..9fd705a 100644
--- a/index.md
+++ b/index.md
@@ -17,3 +17,5 @@ This is entirely a work-in-progress, and should not be relied upon to be stable
 [Read the Syntax chapter of the spec.](syntax.md)
 
 # Semantics
+
+[![Creative Commons BY-SA License](https://i.creativecommons.org/l/by-sa/4.0/80x15.png)](http://creativecommons.org/licenses/by-sa/4.0/)