Update RubyMotion.gitignore

RubyMotion.gitignore

@@ -2,7 +2,7 @@
 build
 tags
 
-# common annoyance editors
+# Editor files
 .DS_Store
 nbproject
 .redcar
@@ -10,4 +10,10 @@ nbproject
 *.swo
 ~
 .eprj
+vendor/Pods
+*.nib
 
+# YARD artifacts
+.yardoc
+_yardoc
+doc/