Ignore generated README.recipes.md

No-Try: true
Change-Id: I9ecabb4e2427bf84d81d9f0f3250038e8162bea7
Reviewed-on: https://skia-review.googlesource.com/64220
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
diff --git a/.gitignore b/.gitignore
index 7705bdf..d70389d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,6 +16,7 @@
 bower_components
 common
 imgui.ini
+infra/bots/README.recipes.md
 infra/bots/gen_tasks_aux.go
 infra/bots/tools/luci-go/linux64/cipd
 infra/bots/tools/luci-go/linux64/isolate