Move contribution info to readme, delete contributing.md

[taanguyen]

Transfer contribution info to README.md

Contributing.md is not used. Transfer contributing steps to README.md, making contribution information easily accessible to developers.

Note to Hacktoberfest reviewers: I'm not trying to create a spammy PR! this was a change requested by the maintainers.

Description

I'm transferring the contribution information and troubleshooting guide to the README, preserving the in action screenshots in the README.

Motivation and Context

Motivation for this PR is to make contribution steps and relevant information readily available for new contributors. First-timer friendly instructions have been tested and verified.

Types of changes

• 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 change)
• Chore (improves application but is not new functionality nor a bug fix)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.