DOCSP-35888 Add missing redirects (#161)

Author: jordan-smith721

config/redirects

@@ -2,12 +2,16 @@ define: prefix docs/drivers/csharp
 define: base https://www.mongodb.com/${prefix}
 define: versions v2.19 v2.20 v2.21 v2.22 v2.23 master
 
+symlink: current -> master
+
 raw: ${prefix}/ -> ${base}/current/
 raw: ${prefix}/stable -> ${base}/current/
+raw: ${prefix}/master -> ${base}/upcoming/
 
 [*-master]: ${prefix}/${version}/fundamentals/connection/network-compression/ -> ${base}/${version}/
 [*-master]: ${prefix}/${version}/fundamentals/crud/write-operations/change/ -> ${base}/${version}/fundamentals/crud/write-operations/modify/
 [*-master]: ${prefix}/${version}/fundamentals/data-formats/guid-serialization/ -> ${base}/${version}/fundamentals/serialization/guid-serialization/
 [*-master]: ${prefix}/${version}/fundamentals/data-formats/poco/ -> ${base}/${version}/fundamentals/serialization/poco/
 [*-master]: ${prefix}/${version}/fundamentals/data-formats/polymorphism/ -> ${base}/${version}/fundamentals/serialization/polymorphic-objects/
+[*-master]: ${prefix}/${version}/fundamentals/data-formats/bson/ -> ${base}/${version}/fundamentals/bson/
 [*-master]: ${prefix}/${version}/fundamentals/class-mapping/ -> ${base}/${version}/fundamentals/serialization/class-mapping/