fix(docs): Move developer specific docs from README.md to CONTRIBUTING.md

[dagardner-nv]

• Move the section regarding the test examples to CONTRIBUTING.md, this information is developer specific and resulted in broken links on pypi.org
• Remove the table of contents, as the anchor tags were similarly broken on pypi.org
• Misc spelling error fix.

Closes #121

[jameslamb]

Thanks for this!

I support these changes to make the README a bit better-suited to also being the PyPI.org homepage for the project.

Just one more suggestion... there's one more anchor reference that'll be broken. I think this line can just be removed completely:

dependency-file-generator/README.md

Line 39 in e26f935

> The [Examples](#examples) section below has instructions on where example `dependency.yaml` files and their corresponding output can be viewed.

[dagardner-nv]

Thanks for this!

I support these changes to make the README a bit better-suited to also being the PyPI.org homepage for the project.

Just one more suggestion... there's one more anchor reference that'll be broken. I think this line can just be removed completely:

dependency-file-generator/README.md

Line 39 in e26f935

> The [Examples](#examples) section below has instructions on where example `dependency.yaml` files and their corresponding output can be viewed.

Done