[Documentation]: Fix broken links pointing to restructured CometBFT v1 documentation

[andynog]

Summary

As part of the CometBFT v1 future release, the documentation for CometBFT was re-structured to implement the diataxis framework structure.

External links pointing to a future v1 documentation site will be broken if not adapted. CometBFT documentation doesn't support re-directs.

Since CometBFT links are versioned (e.g. https://docs.cometbft.com/v0.38/introduction/), any new SDK release should update the links anyway (at least update the version in the URL).

In this particular case, the links also have moved, so there will be an extra effort to locate where the documents moved to. They are new under one of the four "topics" of the diataxis framework:

• explanation
• guides
• references
• tutorials

You can see the new structure here.

The CometBFT team (@andynog) will assist the SDK team with the effort of locating the new docs to fix the broken links.

NOTE: The existing documentation for CometBFT releases before v1 (v0.38.x and under) were not altered, and since the SDK also uses versioned docs I believe these docs for the SDK releases before v1 should not have been impacted.