next release v0.3.8

[casperdcl]

• CLI: enforce strict argument parsing (Enforce strict argument parsing #493)
• Docker: update tags & refactor build (Refactor GitHub Actions release workflow and Dockerfile #494)
  • tag convention: dvgorg/cml:0-dvc{1,2}-base{0,1} (CML docker version tagging #217)
  • py3.8: base1 (Updating python3 version on dvcorg/cml-py3:runner #360)
  • add alternate registry: ghcr.io (Add support for GitHub Container Registry #500 <- Investigate GitHub Docker registry #267)
• misc documentation updates
  • REPO_TOKEN (deprecate repo_token) (docs: repo_token => REPO_TOKEN #492)
  • docker tags (docs: image tags #499)
• misc test updates (review all workflows #498)
  • fix bot tests
  • fix potential security issues
• misc tidy (review all workflows #498)
  • lint YAML (lint YAML #497)
• bump version
• follow-up: update gitlab workflow tag

---

• closes Enforce strict argument parsing #493
• closes docs: image tags #499
• closes Refactor GitHub Actions release workflow and Dockerfile #494
  • fixes CML docker version tagging #217
  • fixes Updating python3 version on dvcorg/cml-py3:runner #360
• closes Add support for GitHub Container Registry #500
  • fixes Investigate GitHub Docker registry #267
• closes review all workflows #498
• closes docs: repo_token => REPO_TOKEN #492
• closes lint YAML #497