Refresh go-bgld README for Bitgesell

[manuelsampedro1]

Summary

• refresh the README package description and Go Reference links for the Bitgesell module
• replace the stale upstream Travis/go-bitcoind badge and legacy Ginkgo install steps with the current go test ./... flow
• clean up the usage example so it is valid Go with concrete Bitgesell defaults

Validation

• checked stale README references with rg for upstream go-bitcoind/Godoc wording
• git diff --check
• Go tests were not run locally because the Go toolchain is not installed in this environment

[MyTH-zyxeon]

Review-assist note for Bitgesell #81.

This looks like a clean README-only modernization pass, and the visible diff fixes multiple stale signals at once: the package badge/doc link now points at the official BitgesellOfficial/go-bgld module, the usage example is valid Go instead of placeholder pseudo-code, and the test section drops the old Ginkgo/Travis-specific flow in favor of go test ./....

If maintainers want a narrow acceptance checklist before merge/payout, I would keep it to these points:

• Confirm the pkg.go.dev/github.com/bitgesellofficial/go-bgld badge/doc URL resolves to the intended canonical module path, including exact casing.
• Spot-check that the refreshed sample compiles as documentation: bgld.New(host, port, user, password, useSSL) matches the current constructor signature, and the shown wallet/RPC helpers still exist under the exported API.
• Keep the README honest about validation scope: the PR author explicitly did not run Go tests locally, so if maintainers care about runtime proof, go test ./... on a clean checkout is the only extra signal really needed.
• Treat this as docs/onboarding scope under the #81 improvement lane, not a runtime/node behavior change.

I did not install dependencies, run Go builds/tests, start a node, use wallet keys, or perform any live-chain action. This is a maintainer-facing review checklist to help decide whether #4 is ready to accept as a focused documentation refresh.