Implement standardized build pipeline based on existing repos

[pritamghanghas]

As a user of this repository, any new push should result in workflow triggers that do linting and dockerfile builds.

• cleanup the dockerfile build and startup script.
• verify that gateway miner runs on the device with ecc.
• update workflow trigger similar to hm-miner

Acceptance Criterion

• a new release of upstream gateway-rs results in auto bumping the dockerfile and corresponding dispatch to helium-miner-software
• Linting workflow actions for dockerfile, code, spellcheck and security. Copy linting settings from hm-confing and hotspot-production-tool.
• docker builds on every push.
• Add CODEOWNERS and CONTRIBUTING. Copy from existing repos.
  • Device team should be code owners.

[marvinmarnold]

@pritamghanghas FYI I just updated the AC