more redirect tweaks (#460)

Author: jeff-allen-mongo

config/redirects

@@ -1,5 +1,5 @@
 define: base https://docs.mongodb.com
-define: versions v2.2 v2.4 v2.6 v3.0 v3.2 v3.4 v3.6 v4.0 v4.2 v4.4 v5.0 v5.2 master
+define: versions v2.2 v2.4 v2.6 v3.0 v3.2 v3.4 v3.6 v4.0 v4.2 v4.4 v5.0 v5.1 v5.2 master
 symlink: manual -> v5.0
 symlink: upcoming -> v5.0
 symlink: master -> v5.0
@@ -1802,7 +1802,7 @@ raw: /manual/core/wildcard -> ${base}/manual/core/index-wildcard/
 # Redirects for 5.2 and greater (if pages are removed in 5.2 that used to exist in earlier versions)
 #
 
-(v5.1-*]: /${version}/reference/command/availableQueryOptions -> ${base}/${version}/reference/command
+[v5.2-*]: /${version}/reference/command/availableQueryOptions -> ${base}/${version}/reference/command
 
 #
 # Redirects for new 5.1 pages
@@ -1908,7 +1908,7 @@ raw: /manual/core/wildcard -> ${base}/manual/core/index-wildcard/
 # Redirects for 5.1 and greater (if pages are removed in 5.0 that used to exist in earlier versions)
 #
 
-[v5.0-*]: /${version}/core/core/authentication-mechanisms -> ${base}/${version}/core/authentication
+(v5.0-*]: /${version}/core/core/authentication-mechanisms -> ${base}/${version}/core/authentication
 (v5.0-*]: /${version}/reference/operator/meta/comment -> ${base}/${version}/reference/method/js-cursor/
 (v5.0-*]: /${version}/reference/operator/meta/explain -> ${base}/${version}/reference/method/js-cursor/
 (v5.0-*]: /${version}/reference/operator/meta/hint -> ${base}/${version}/reference/method/js-cursor/