NATS module documentation cannot be accessed via nats by-examples

[grainier]

Description: NATS module documentation cannot be accessed using the link provided in the nats-streaming-client example page.

Affected Product Version: alpha3

OS, Browser, other environment details and versions:

Steps to reproduce:

1. Visit https://ballerina.io/learn/by-example/nats-streaming-client.html
2. Click on the link to the NATS module documentation.
3. Which redirects to https://docs.central.ballerina.io/ballerinax/nats/* a 404.

Related Issues: n/a

[Kishanthan]

Accessing an old version works - https://docs.central.ballerina.io/ballerinax/nats/1.1.0-alpha3

But, if a version page is working, then landing at root like https://docs.central.ballerina.io/ballerinax/nats/ should not give a 404 at-least