Add RELEASING.md (#643)

Author: pmcollins

RELEASING.md

@@ -0,0 +1,32 @@
+# Releasing splunk-opentelemetry
+
+This document describes the steps to release a new version of the `splunk-opentelemetry` package.
+
+Steps to release a new version:
+
+1) Create a new branch from `main`
+2) Bump dependency versions in pyproject.toml
+    - update otel dependencies to the latest versions, e.g.:
+        - `"opentelemetry-exporter-otlp-proto-http==1.36.0"`
+        - `"opentelemetry-instrumentation==0.57b0"`
+3) Bump our version in __about__.py
+4) Update additional version string locations
+    - `ott_lib.py` # this file is used as a library for integration tests
+    - `docker/requirements.txt` # this file is used to build the docker init image for the operator
+    - `docker/example-instrumentation.yaml`  # this file is just an example but would be nice to show the latest version
+5) Add a new entry in CHANGELOG.md
+6) Commit the changes with a message like "Bump version to 3.4.5"
+    - you may want to use multiple commits for clarity, e.g.:
+        - bump dependency versions
+        - bump our version in `__about__.py`
+        - update additional version string locations
+        - update CHANGELOG.md
+7) Push the changes to the Github Splunk OTel Python repo
+8) Open a PR and merge after approval
+9) Navigate to the GitLab mirror and verify that the mirror has pulled the version you just merged by checking the
+   version number in the `__about__.py` file
+10) When ready to release, create a new tag like `v3.4.5` on main in GitLab with the version number
+    - a tag of the format `vX.Y.Z` will trigger the CI pipeline to build and publish the package to PyPI and the Docker image to Quay
+11) Monitor the release pipeline in GitLab to ensure it completes successfully
+12) Post release, verify that the new package is available on PyPI and the Docker image is available on Quay
+13) Smoke test the release locally by installing the new package and running it with a small app