feat(release): prepare first public preview

SUPPORT.md

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+# Support
+
+Magent is an early public release maintained on a best-effort basis. There is no
+paid support or guaranteed response time.
+
+## Start here
+
+- Installation choice: [docs/INSTALLATION.md](docs/INSTALLATION.md)
+- Docker and Compose: [docs/DOCKER.md](docs/DOCKER.md)
+- Portainer: [docs/PORTAINER.md](docs/PORTAINER.md)
+- Native Linux: [docs/NATIVE_INSTALL.md](docs/NATIVE_INSTALL.md)
+- Configuration: [docs/ENVIRONMENT.md](docs/ENVIRONMENT.md)
+- Backup and restore: [docs/installation-and-recovery.md](docs/installation-and-recovery.md)
+
+## Ask for help or report a problem
+
+Use the matching issue template at
+https://git.amslabs.net/Rephl3x/Magent-Public/issues/new.
+
+Include the Magent version/tag and image digest, CPU architecture, installation
+method, browser, exact reproduction steps, expected result and sanitized logs.
+Say whether the problem survives a normal restart. Never attach `.env` files,
+databases, backups, generated secret files, API keys, passwords, access tokens,
+private URLs or personal viewing data.
+
+Feature requests should describe the problem and intended user, not only a
+proposed implementation. Integration requests should link to the upstream
+application's public API documentation.
+
+For a vulnerability, follow [SECURITY.md](SECURITY.md) instead of opening a
+detailed public report.