#1113 Link uml-reverse-mapper created class diagrams to readme, where needed

double-checked-locking/README.md

@@ -16,6 +16,7 @@ locking criterion (the "lock hint") without actually acquiring the lock. Only
 if the locking criterion check indicates that locking is required does the
 actual locking logic proceed.
 
+## Class diagram
 ![alt text](./etc/double_checked_locking_1.png "Double Checked Locking")
 
 ## Applicability