Merge branch 'v5.1' into v5.1

Author: shuangela

config/redirects

@@ -7,3 +7,4 @@ define: versions v5.1 master
 raw: ${prefix}/ -> ${base}/current/
 raw: ${prefix}/master -> ${base}/upcoming/
 [v5.1-*]: ${prefix}/${version}/get-started/connect-to-mongodb -> ${base}/${version}/get-started/run-sample-query/
+