dev: Use default .github files (#338)

packages/contracts/.github/CONTRIBUTING.md

-# Contributing
-
-When contributing to this repository, please first discuss the change you wish to make via issue,
-email, or any other method with the owners of this repository before making a change. 
-
-Please note we have a code of conduct, please follow it in all your interactions with the project.
-
-## Pull Request Process
-
-1. Ensure that tests pass and code is lint free: `npm test`
-2. Update the README.md if any changes invalidate its current content.
-3. Include any tests for new functionality.
-4. Reference any revelant issues in your PR comment.
-
-## Code of Conduct
-
-### Our Pledge
-
-In the interest of fostering an open and welcoming environment, we as
-contributors and maintainers pledge to making participation in our project and
-our community a harassment-free experience for everyone, regardless of age, body
-size, disability, ethnicity, gender identity and expression, level of experience,
-nationality, personal appearance, race, religion, or sexual identity and
-orientation.
-
-### Our Standards
-
-Examples of behavior that contributes to creating a positive environment
-include:
-
-* Using welcoming and inclusive language
-* Being respectful of differing viewpoints and experiences
-* Gracefully accepting constructive criticism
-* Focusing on what is best for the community
-* Showing empathy towards other community members
-
-Examples of unacceptable behavior by participants include:
-
-* The use of sexualized language or imagery and unwelcome sexual attention or
-advances
-* Trolling, insulting/derogatory comments, and personal or political attacks
-* Public or private harassment
-* Publishing others' private information, such as a physical or electronic
-  address, without explicit permission
-* Other conduct which could reasonably be considered inappropriate in a
-  professional setting
-
-### Our Responsibilities
-
-Project maintainers are responsible for clarifying the standards of acceptable
-behavior and are expected to take appropriate and fair corrective action in
-response to any instances of unacceptable behavior.
-
-Project maintainers have the right and responsibility to remove, edit, or
-reject comments, commits, code, wiki edits, issues, and other contributions
-that are not aligned to this Code of Conduct, or to ban temporarily or
-permanently any contributor for other behaviors that they deem inappropriate,
-threatening, offensive, or harmful.
-
-### Scope
-
-This Code of Conduct applies both within project spaces and in public spaces
-when an individual is representing the project or its community. Examples of
-representing a project or community include using an official project e-mail
-address, posting via an official social media account, or acting as an appointed
-representative at an online or offline event. Representation of a project may be
-further defined and clarified by project maintainers.
-
-### Enforcement
-
-Instances of abusive, harassing, or otherwise unacceptable behavior may be
-reported by contacting the project team at contributing@optimism.io. All
-complaints will be reviewed and investigated and will result in a response that
-is deemed necessary and appropriate to the circumstances. The project team is
-obligated to maintain confidentiality with regard to the reporter of an incident.
-Further details of specific enforcement policies may be posted separately.
-
-Project maintainers who do not follow or enforce the Code of Conduct in good
-faith may face temporary or permanent repercussions as determined by other
-members of the project's leadership.
-
-### Attribution
-
-This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
-available at [http://contributor-covenant.org/version/1/4][version] and from the [Angular Seed Contributing Guide][angular-contrib].
-
-[homepage]: http://contributor-covenant.org
-[version]: http://contributor-covenant.org/version/1/4/
-[angular-contrib]: https://github.com/mgechev/angular-seed/blob/master/.github/CONTRIBUTING.md

packages/contracts/.github/ISSUE_TEMPLATE/bug_report.md

----
-name: Bug report
-about: Create a report to help us improve
-title: ''
-labels: ''
-assignees: ''
-
----
-
-**Describe the bug**
-A clear and concise description of the bug.
-
-**Steps to reproduce**
-Steps to reproduce the behavior:
-1. 
-2.
-3.
-
-**Expected behavior**
-A clear and concise description of what you expected to happen.
-
-**Screenshots**
-If applicable, add screenshots to help explain your problem.
-
-**Specifications**
- - Version:
- - OS:
- - Node Version:
-
-**Additional context**
-Add any other context about the problem here.

packages/contracts/.github/ISSUE_TEMPLATE/feature_request.md

----
-name: Feature request
-about: Suggest an idea for this project
-title: ''
-labels: ''
-assignees: ''
-
----
-
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is.
-
-**Describe the solution you'd like**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Additional context**
-Add any other context or screenshots about the feature request here.

packages/contracts/.github/PULL_REQUEST_TEMPLATE.md

-## Description
-
-## Questions
-- 
--
--
-
-## Metadata
-### Fixes
-- Fixes # [Link to Issue]
-
-## Contributing Agreement
-<!--
-You *must* read and fully understand our Contributing Guide and Code of Conduct before submitting this pull request. Strong, healthy, and respectful communities are the best way to build great code 💖.
--->
-
-- [ ] I have read and understood the [Optimism Contributing Guide and Code of Conduct](https://github.com/ethereum-optimism/optimism-monorepo/blob/master/.github/CONTRIBUTING.md) and am following those guidelines in this pull request.