docs(CONTRIBUTING): sketch out release process

Author: michaelfig

CONTRIBUTING.md

@@ -0,0 +1,37 @@
+Rough notes that should evolve into a better guide sometime.
+
+## Publishing a release
+
+```sh
+# Name a release branch
+now=`date -u +%Y%m%dT%H%M%S`
+git checkout -b prepare-release-$now
+git branch -u origin
+
+# Install build dependencies
+yarn install --force
+
+# Bump versions for changed packages
+yarn lerna version --conventional-graduate
+
+# Push and create a release PR
+git push
+open https://github.com/endojs/Jessie/pulls
+```
+
+Get approval and wait for CI to pass.
+
+```sh
+# Build release artifacts.
+yarn build
+
+# Publish to NPM. NOTE: You may have to repeat this several times if there are failures.
+# without concurrency until https://github.com/Agoric/agoric-sdk/issues/8091
+yarn lerna publish --concurrency 1 from-package
+```
+
+Merge the release PR into the base branch.
+
+**DO NOT REBASE OR SQUASH OR YOU WILL LOSE REFERENCES TO YOUR TAGS.**
+
+You may use the GitHub "Merge" button directly instead of automerge.