Add devcontainer specifications to cookiecutter-poetry and child projects

[kenibrewer]

PR Checklist

• [x] A description of the changes is added to the description of this PR.
• [x] If there is a related issue, make sure it is linked to this PR.
• [x] If you've fixed a bug or added code that should be tested, add tests!
• [x] Documentation in docs is updated

Description of changes

This PR adds devcontainer specifications to both the cookiecutter-poetry project and child projects created from it. Devcontainers provide a reproducible environment that have all required software dependencies pre-installed and configure aspects of the testing and development workflows.

Fixes #94

[kenibrewer]

@fpgmaas This is ready for review

[codecov[bot]]

Codecov Report

Merging #95 (3788593) into main (49756a7) will not change coverage. Report is 1 commits behind head on main. The diff coverage is n/a.

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  Coverage   0.00%   0.00%           
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  Lines          5       5           
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  Misses         5       5           

[fpgmaas]

Merged. Thanks @kenibrewer! Great addition to the project.