feat(docker): add dev `Dockerfile.dev` with `PHP8` and `Xdebug` inside

[rustatian]

Reason for This PR

closes: #61

Description of Changes

• Add dev Dockerfile with PHP and Xdebug inside.

License Acceptance

By submitting this pull request, I confirm that my contribution is made under the terms of the MIT license.

PR Checklist

[Author TODO: Meet these criteria.] [Reviewer TODO: Verify that these criteria are met. Request changes if not]

• [x] All commits in this PR are signed (git commit -s).
• [x] The reason for this PR is clearly provided (issue no. or explanation).
• [x] The description of changes is clear and encompassing.
• [x] Any required documentation changes (code and docs) are included in this PR.
• [x] Any user-facing changes are mentioned in CHANGELOG.md.
• [x] All added/changed functionality is tested.

[codecov[bot]]

Codecov Report

Merging #66 (3999fbc) into master (b81f3b2) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #66   +/-   ##
=======================================
  Coverage   50.98%   50.98%           
=======================================
  Files          11       11           
  Lines         306      306           
=======================================
  Hits          156      156           
  Misses        139      139           
  Partials       11       11           

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update b81f3b2...3999fbc. Read the comment docs.