add CONTRIBUTING, code of conduct, roadmap (ko-build#837)

Author: imjasonh

CONTRIBUTING.md

@@ -21,3 +21,16 @@ All submissions, including submissions by project members, require review. We
 use GitHub pull requests for this purpose. Consult
 [GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
 information on using pull requests.
+
+## Testing
+
+Ensure the following passes:
+```
+./hack/presubmit.sh
+```
+and commit any resultant changes to `go.mod` and `go.sum`. To update any docs
+after client changes, run:
+
+```
+./hack/update-codegen.sh
+```

ROADMAP.md

@@ -0,0 +1,21 @@
+# `ko` Project Roadmap
+
+_Last updated October 2022_
+
+- Foster a community of contributors and users
+  - give talks, do outreach, expand the pool of contributors
+  - identify projects that could benefit from using `ko`, and help onboard them
+  - publish case studies from successful migrations
+
+- Integrate [sigstore](https://sigstore.dev) for built artifacts
+  - attach signed SBOMs
+  - attach signed provenance attestations
+  - support the OCI referrers API and [fallback tag scheme](https://github.com/opencontainers/distribution-spec/blob/main/spec.md#referrers-tag-schema)
+  - integrate with CI workload identity (e.g., GitHub OIDC) to keylessly sign artifacts
+
+- Faster builds
+  - identify unnecessary work and avoid it when possible
+
+- Ecosystem integrations
+  - support Terraform provider, and potentially Pulumi and CDK, others
+  - provide working examples of these integrations

code-of-conduct.md

@@ -0,0 +1,76 @@
+# Contributor Covenant 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, education, socio-economic status, 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
+
+<!-- TODO: Need a real CoC contact list. -->
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team. 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
+https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+
+[homepage]: https://www.contributor-covenant.org