docs: add contributing (#138)

CONTRIBUTING.md

@@ -0,0 +1,75 @@
+# Contributing to opentelemetry-go-build-tools
+
+## Development
+
+You can view and edit the source code by cloning this repository:
+
+```sh
+git clone /~https://github.com/open-telemetry/opentelemetry-go-build-tools.git
+```
+
+Run `make test` to run the tests instead of `go test`.
+
+There are some generated files checked into the repo. To make sure
+that the generated files are up-to-date, run `make` (or `make
+precommit` - the `precommit` target is the default).
+
+The `precommit` target also fixes the formatting of the code and
+checks the status of the go module files.
+
+If after running `make precommit` the output of `git status` contains
+`nothing to commit, working tree clean` then it means that everything
+is up-to-date and properly formatted.
+
+## Pull Requests
+
+### How to Send Pull Requests
+
+Everyone is welcome to contribute code to `opentelemetry-go-build-tools` via
+GitHub pull requests (PRs).
+
+Open a pull request against the main `opentelemetry-go-build-tools` repo.
+Be sure to add the pull request ID to the entry you added to `CHANGELOG.md`.
+
+### How to Receive Comments
+
+* If the PR is not ready for review, please put `[WIP]` in the title,
+  tag it as `work-in-progress`, or mark it as
+  [`draft`](https://github.blog/2019-02-14-introducing-draft-pull-requests/).
+* Make sure CLA is signed and CI is clear.
+
+### How to Get PRs Merged
+
+A PR is considered to be **ready to merge** when:
+
+* It has received two approvals from Collaborators/Maintainers (at
+  different companies). This is not enforced through technical means
+  and a PR may be **ready to merge** with a single approval if the change
+  and its approach have been discussed and consensus reached.
+* Feedback has been addressed.
+* Any substantive changes to your PR will require that you clear any prior
+  Approval reviews, this includes changes resulting from other feedback. Unless
+  the approver explicitly stated that their approval will persist across
+  changes it should be assumed that the PR needs their review again. Other
+  project members (e.g. approvers, maintainers) can help with this if there are
+  any questions or if you forget to clear reviews.
+* It has been open for review for at least one working day. This gives
+  people reasonable time to review.
+* Trivial changes (typo, cosmetic, doc, etc.) do not have to wait for
+  one day and may be merged with a single Maintainer's approval.
+* `CHANGELOG.md` has been updated to reflect what has been
+  added, changed, removed, or fixed.
+* `README.md` has been updated if necessary.
+* Urgent fix can take exception as long as it has been actively
+  communicated.
+
+Any Maintainer can merge the PR once it is **ready to merge**.
+
+## Approvers and Maintainers
+
+[CODEOWNERS](/~https://github.com/open-telemetry/opentelemetry-go-build-tools/blob/main/.github/CODEOWNERS)
+
+### Become an Approver or a Maintainer
+
+See the [community membership document in OpenTelemetry community
+repo](/~https://github.com/open-telemetry/community/blob/main/community-membership.md).

README.md

@@ -1,2 +1,6 @@
 # opentelemetry-go-build-tools
-Build tools for use by the Go API/SDK, the collector, and their associated contrib repositories
+
+Build tools for use by the Go API/SDK, the collector, and their associated
+contrib repositories
+
+[Contributing](CONTRIBUTING.md)