docs: add a governance document

Since there have been disagreements on certain aspects of the technical
direction, let's clear things up, and introduce a governance document,
taking inspiration from:

https://github.com/uapi-group/uapi-group.github.io/blob/main/content/_index.md#governance

docs/GOVERNANCE.md

@@ -0,0 +1,44 @@
+---
+title: Governance
+category: Contributing
+layout: default
+SPDX-License-Identifier: LGPL-2.1-or-later
+---
+
+The systemd project is governed as a Free Software project, with the following rules:
+
+1. Anyone is welcome to submit comments and reviews.
+
+2. Every project maintainer has the right to merge changes, if they feel that
+   they hold the expertise in the specific area.
+
+3. Except for trivial changes, an approval from at least one project maintainer
+   who is not the author is required before merging.
+
+4. Regular contributors may be invited to join the project maintainers team.
+
+5. If there's disagreement whether technical changes should be merged or not,
+   and attempts to resolve the situation amicably didn't result in a solution,
+   the subsystem maintainer makes the final decision. If a subsystem has no
+   specific maintainer, then the project leader has the final say.
+
+6. Changes to the list of maintainers or this governance document require a
+   simple majority vote of all maintainers.
+
+# Maintainers
+
+Currently, the project maintainers are as follows (in alphabetical order):
+
+* Daan De Meyer
+* Lennart Poettering
+* Luca Boccassi
+* Mike Yuan
+* Yu Watanabe
+* Zbigniew Jędrzejewski-Szmek
+
+Currently, subsystem maintainers are as follows:
+
+* systemd-networkd, systemd-udevd: Yu Watanabe
+* systemd-repart, mkosi, integration tests: Daan De Meyer
+
+Currently, the project leader is: Lennart Poettering