fix graph

Author: Benjamin Trigona-Harany

content/pages/leaving-earth/index.md

@@ -178,7 +178,7 @@ graph TD
     E((Earth)) -->|3| ESo(Suborbital Flight)
     ESo -->|5| Eo
     E   -->|8| Eo(Earth Orbit)
-    subgraph
+    subgraph M
     Eo  ==>|3| Lo(Lunar Orbit)
     Lo  ==>|2| L(Moon)
     end