Create the config.yml file for the Welcome Bot

## Description
As a first time contributor,
I need a bot to help guide my first contribution,
so that I can follow this org's contribution guidelines.

## Mocks

## Acceptance Criteria
### Update [Required]
* [ ] newIssueWelcomeComment is complete with the correct links to this repo.
* [ ] newPRWelcomeComment is complete with the links to the project's stream or topic and the repo's Code of Conduct.
* [ ] firstPRMergeComment is complete.

## Definition of Done
* [ ] All of the required items are completed.
* [ ] Approval by 1 mentor.

## Estimation
0.5 hours