.hgignore: add doc/codelab/wiki/*.bin

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/4173063
diff --git a/.hgignore b/.hgignore
index 75936d6..453a712 100644
--- a/.hgignore
+++ b/.hgignore
@@ -21,6 +21,7 @@
 _testmain.go
 y.tab.[ch]
 doc/htmlgen
+doc/codelab/wiki/*.bin
 misc/cgo/life/run.out
 misc/dashboard/builder/gobuilder
 misc/goplay/goplay