docs: refresh official Docker repo links

[Luzijano]

Summary

• Point README links at the official BitgesellOfficial/bgld-docker repository instead of the original contributor fork.
• Fix the Bitgesell spelling in the quick-start text.
• Fix the documented test runner path from tests/run.sh to the actual test/run.sh path.

Validation

• Verified updated official GitHub/raw URLs resolve successfully.
• Ran shell syntax validation:

  bash -n docker-entrypoint.sh bin/bgl_init bin/bgl_oneshot bootstrap-host.sh test/run.sh test/tests/*.sh

• Verified the documented test runner path works against the locally built image:

  ./test/run.sh bgld-autopilot-test:latest

• Prior build validation for the same checkout:

  docker build -t bgld-autopilot-test .

Related bounty/improvement context: Bitgesell official Docker image / contributor onboarding polish under the public Bitgesell bounty/improvement program.

[MyTH-zyxeon]

Maintainer-facing review assist for the Bitgesell #81 improvement-program queue:

I rechecked this PR at head e52914ed187b12eab4ea2a6b12a1ab06c4810858. It is a small docs-only cleanup across README.md and test/README.md, and it is currently OPEN/MERGEABLE/CLEAN with no prior PR comments or reviews.

Suggested acceptance checks before merge:

• confirm the official-repo link switch is intentional for every touched URL: image asset, raw bootstrap-host.sh, and docs folder;
• decide whether the quick-start Docker image name should remain naftalimurgor/bgld for the currently published image, or whether docs should also point at an official image/tag if one exists;
• verify the one-line bootstrap command against the current default branch name (main) and make sure bootstrap-host.sh still supports pipe-to-shell usage safely enough for docs;
• keep the test/run.sh correction, since the repository has test/README.md and test/run.sh, not tests/run.sh;
• classify this under #81 as onboarding/docs polish rather than a runtime-hardening payout unless maintainers want a follow-up PR for image publication or bootstrap safety.

No runtime or consensus behavior changes are introduced by this PR; the only merge risk I see is the Docker image ownership/tag wording.