Doc links to website with paused deployment

[PoorlyDefinedBehaviour]

The documentation links in https://github.com/dgraph-io/badger?tab=readme-ov-file#badger-documentation link to a webpage with the following message:

Link: https://hypermode.com/blog/badger-txn/

[matthewmcneely]

It's been moved to https://badger.dgraph.io