Networking troubleshooting for end users is unclear

[stirby]

Our enterprise customers have noted that diagnosing networking latency from within the VSCode extension is difficult. The extension shows real-time latency, but does not offer assistance on how to improve performance.

Since many developers interact with Coder exclusively through VSCode, this is a great location to add finer-grained diagnostic tooling, or simply links to documentation on how to troubleshoot networking problems as a user.

This could be as simple as linking our Networking Troubleshooting documentation. We could link to the most relevant section of this documentation given a user's connection type as it's already detected by the extension.