DOP-1883: update TOC link to use canonical node docs URL (#728)

Author: schmalliso

source/index.txt

@@ -18,7 +18,7 @@ MongoDB Drivers
    C# and .NET Driver </csharp>
    Go Driver </go>
    Java Drivers </java-drivers>
-   Node.js Driver <https://docs.mongodb.com/drivers/node>
+   Node.js Driver <https://docs.mongodb.com/drivers/node/current/>
    PHP Driver </php>
    Python Drivers </python>
    Ruby Driver  <https://docs.mongodb.com/ruby-driver/current/>