Update implementation documentation.
diff --git a/org.jacoco.doc/docroot/doc/implementation.html b/org.jacoco.doc/docroot/doc/implementation.html
index b9306ce..43b7b35 100644
--- a/org.jacoco.doc/docroot/doc/implementation.html
+++ b/org.jacoco.doc/docroot/doc/implementation.html
@@ -47,7 +47,7 @@
   diagram gives an overview with the techniques used by JaCoCo highlighted:

 </p>

 

-<img src=".resources/implementation-1.png" alt="Coverage Implementation Techniques"/>

+<img src=".resources/implementation.png" alt="Coverage Implementation Techniques"/>

 

 <p>

   Byte code instrumentation is very fast, can be implemented in pure Java and