Update dev environment instructions and other small improvements

[snekiam]

Open to feedback, this is readable/followable to me but it may not be for others.

What's New?

New documentation for setting up a dev environment, as well as some minor improvements to the readme.

Type of change (pick-one)

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [x] This change requires a documentation update

How Has This Been Tested?

Steps were based on helping get people setup last week, as well as the Dockerfile.

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!

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