Merge pull request MicrosoftDocs#104 from ellerkelso/patch/ignore-build

Add build dir to gitignore

Author: Colin Robertson

.gitignore

@@ -7,3 +7,6 @@ _themes.MSDN.Modern/
 _themes.VS.Modern/
 
 .openpublishing.buildcore.ps1
+
+# Documentation build
+/docs/vcppdocs