release.rst in embulk-0.6.18

- old
+ new

@@ -2,9 +2,10 @@
 ==================================
 
 .. toctree::
     :maxdepth: 1
 
+    release/release-0.6.18
     release/release-0.6.17
     release/release-0.6.16
     release/release-0.6.15
     release/release-0.6.14
     release/release-0.6.13