Add link to how to manually connect to a workspace in the version mismatch warning

[fioan89]

Version mismatch warning should tell users that they can fallback on the Gateway + SSH Plugin to connect to a Coder Workspace. Something similar to:

The link to the documentation:
https://coder.com/docs/coder-oss/latest/ides/gateway#creating-a-new-jetbrains-gateway-connection