Add CONTRIBUTING file (open-telemetry#127)

Co-authored-by: Christos Kalkanis <[email protected]>
Co-authored-by: Florian Lehner <[email protected]>
Co-authored-by: Joel Höner <[email protected]>
Co-authored-by: Tim Rühsen <[email protected]>

CONTRIBUTING.md

@@ -0,0 +1,149 @@
+# Contributing to opentelemetry-ebpf-profiler
+
+The Profiling special interest group (SIG) meets regularly. See the
+OpenTelemetry
+[community](https://github.com/open-telemetry/community)
+repo for information on this and other SIGs.
+
+## Community
+
+See the [public meeting
+notes](https://docs.google.com/document/d/19UqPPPlGE83N37MhS93uRlxsP1_wGxQ33Qv6CDHaEp0/edit#heading=h.4rdgawyis2hd)
+for a summary description of past meetings.
+
+See the [calendar
+group](https://groups.google.com/a/opentelemetry.io/g/calendar-profiling) to
+get invited to meetings.
+
+See the [#otel-profiles](https://cloud-native.slack.com/archives/C03J794L0BV)
+slack channel for discussions and questions.
+
+## Development
+
+You can view and edit the source code by cloning this repository:
+
+```sh
+git clone https://github.com/open-telemetry/opentelemetry-ebpf-profiler
+```
+
+Run `make test` to run the tests instead of `go test`.
+
+
+## Pull Requests
+
+### How to Send Pull Requests
+
+Everyone is welcome to contribute code to `opentelemetry-ebpf-profiler` via
+GitHub pull requests (PRs).
+
+To create a new PR, fork the project in GitHub and clone the upstream
+repo:
+
+```sh
+git clone https://github.com/open-telemetry/opentelemetry-ebpf-profiler
+```
+
+This will put the project in `opentelemetry-ebpf-profiler` in
+current working directory.
+
+Enter the newly created directory and add your fork as a new remote:
+
+```sh
+git remote add <YOUR_FORK> [email protected]:<YOUR_GITHUB_USERNAME>/opentelemetry-ebpf-profiler
+```
+
+Check out a new branch, make modifications, run linters and tests, and push the
+branch to your fork:
+
+```sh
+git checkout -b <YOUR_BRANCH_NAME>
+# edit files
+# update changelog
+git add -p
+git commit
+git push <YOUR_FORK> <YOUR_BRANCH_NAME>
+```
+
+Open a pull request against the main `opentelemetry-ebpf-profiler` repo.
+
+Avoid rebasing and force-pushing to your branch to facilitate reviewing the
+pull request.
+Rewriting Git history makes it difficult to keep track of iterations during
+code review.
+All pull requests are squashed to a single commit upon merge to `main`.
+
+### 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 **ready to merge** when:
+
+* It has received two qualified approvals[^1].
+
+	This is not enforced through automation, but needs to be validated by the
+	maintainer merging.
+	* PRs introducing changes that have already been discussed and consensus
+		reached only need one qualified approval. The discussion and resolution
+		needs to be linked to the PR.
+
+* All feedback has been addressed.
+	* All PR comments and suggestions are resolved.
+	* All GitHub Pull Request reviews with a status of "Request changes" have
+		been addressed. Another review by the objecting reviewer with a different
+		status can be submitted to clear the original review, or the review can be
+		dismissed by a [Maintainer] when the issues from the original review have
+		been addressed.
+	* Any comments or reviews that cannot be resolved between the PR author and
+		reviewers can be submitted to the community [Approver]s and [Maintainer]s
+		during the weekly SIG meeting. If consensus is reached among the
+		[Approver]s and [Maintainer]s during the SIG meeting the objections to the
+		PR may be dismissed or resolved or the PR closed by a [Maintainer].
+	* Any substantive changes to the PR require existing Approval reviews be
+		cleared unless the approver explicitly states that their approval persists
+		across changes. This includes changes resulting from other feedback.
+		[Approver]s and [Maintainer]s can help in clearing reviews and they should
+		be consulted if there are any questions.
+
+* The PR branch is up to date with the base branch it is merging into.
+	* To ensure this does not block the PR, it should be configured to allow
+		maintainers to update it.
+
+* It has been open for review for at least one working day. This gives people
+	reasonable time to review.
+
+* All required GitHub workflows have succeeded.
+* Urgent fix can take exception as long as it has been actively communicated
+	among [Maintainer]s.
+
+Any [Maintainer] can merge the PR once the above criteria have been met.
+
+[^1]: A qualified approval is a GitHub Pull Request review with "Approve"
+	status from an OpenTelemetry Profiler [Approver] or [Maintainer].
+
+## Approvers and Maintainers
+
+### Approvers
+
+- [Christos Kalkanis](https://github.com/christos68k), Elastic
+- [Florian Lehner](https://github.com/florianl), Elastic
+- [Tim Rühsen](https://github.com/rockdaboot), Elastic
+
+### Maintainers
+
+- [Dmitry Filimonov](https://github.com/petethepig), Pyroscope/Grafana
+- [Felix Geisendörfer](https://github.com/felixge), Datadog
+- [Joel Höner](https://github.com/athre0z), Elastic
+- [Timo Teräs](https://github.com/fabled)
+
+### Become an Approver or a Maintainer
+
+See the [community membership document in OpenTelemetry community
+repo](https://github.com/open-telemetry/community/blob/main/guides/contributor/membership.md).
+
+[Approver]: #approvers
+[Maintainer]: #maintainers