Document the pypi user and how to manage it.

The mention in the release config isn't easily found and I want to make
sure there is some reference for how to manage the account.

DEVELOPING.md

@@ -4,21 +4,37 @@
 
 Start from a clean checkout at `main`.
 
-Before running through the release it's good to run the build and the tests locally, and make sure CI is passing. You can
-also test-drive the commit in an existing Bazel workspace to sanity check functionality.
+Before running through the release it's good to run the build and the tests
+locally, and make sure CI is passing. You can also test-drive the commit in an
+existing Bazel workspace to sanity check functionality.
 
 #### Determining Semantic Version
 
-**rules_python** is currently using [Zero-based versioning](https://0ver.org/) and thus backwards-incompatible API
-changes still come under the minor-version digit. So releases with API changes and new features bump the minor, and
-those with only bug fixes and other minor changes bump the patch digit.   
+**rules_python** is currently using [Zero-based versioning](https://0ver.org/)
+and thus backwards-incompatible API changes still come under the minor-version
+digit. So releases with API changes and new features bump the minor, and those
+with only bug fixes and other minor changes bump the patch digit.
+
+#### Steps
+
+1.  Determine what will be the next release, following semver.
+1.  Create a tag and push, e.g. `git tag 0.5.0 upstream/main && git push
+    upstream --tags`
+1.  Watch the release automation run on
+    https://github.com/bazelbuild/rules_python/actions
 
-#### Steps 
-1. Determine what will be the next release, following semver.
-1. Create a tag and push, e.g. `git tag 0.5.0 upstream/main && git push upstream --tags`
-1. Watch the release automation run on https://github.com/bazelbuild/rules_python/actions
-
 #### After release creation in Github
 
-1. Ping @philwo to get the new release added to mirror.bazel.build. See [this comment on issue #400](https://github.com/bazelbuild/rules_python/issues/400#issuecomment-779159530) for more context.
-1. Announce the release in the #python channel in the Bazel slack (bazelbuild.slack.com). 
+1.  Ping @philwo to get the new release added to mirror.bazel.build. See
+    [this comment on issue #400](https://github.com/bazelbuild/rules_python/issues/400#issuecomment-779159530)
+    for more context.
+1.  Announce the release in the #python channel in the Bazel slack
+    (bazelbuild.slack.com).
+
+## Secrets
+
+### PyPI user rules-python
+
+Part of the release process uploads packages to PyPI as the user `rules-python`.
+This account is managed by Google; contact rules-python-pyi@google.com if
+something needs to be done with the PyPI account.