docs: mirror resolution of #1281 in dev doc

Signed-off-by: Stephan Renatus <srenatus@chef.io>

Documentation/dev-become-a-maintainer.md

+# Join the fun -- become a maintainer!
+
+If a person or their company uses dex, has demonstrated an understanding of this
+project (either by submitting PRs to dex or related projects such as Helm
+charts), and the ability to work productively with the community, that person
+can have write access to this repo. We want to be liberal with this privilege
+and enable companies using dex to have a voice in its development.
+
+The first 10 PRs by new maintainers must be approved by a maintainer from a
+different company.
+
+Access to https://quay.io/dexidp will be restricted to @srenatus, @rithujohn191
+and @ericchiang to prevent new maintainers from being able to unilaterally push
+images.
+
+If you would like access, please email @ericchiang at ericchiang@google.com
+stating your case or open a public issue. Come join the fun 😃