Update 'memory' key to 'mem'

PiperOrigin-RevId: 319841858
diff --git a/site/docs/exec-groups.md b/site/docs/exec-groups.md
index 05820e8..f25147a 100644
--- a/site/docs/exec-groups.md
+++ b/site/docs/exec-groups.md
@@ -131,6 +131,6 @@
 ```
 
 All actions with `exec_group = "link"` would see the exec properties
-dictionary as `{"memory": "16g"}`. As you see here, execution-group-level
+dictionary as `{"mem": "16g"}`. As you see here, execution-group-level
 settings override target-level settings.