Move or remove the duplicated files.

This commit adds the top-level README.md file and moves
the CODE_OF_CONDUCT.md, CONTRIBUTING.md, CONTRIBUTING_GO.md,
CONTRIBUTING_RUST.md, SECURITY.md to top-level directory.

It also removes per-project .cirrus.yml, since they are not used now -
we use the top-level one. Same for .github directories.

Signed-off-by: Jan Kaluza <[email protected]>

Author: jankaluza

common/CODE-OF-CONDUCT.md renamed to CODE-OF-CONDUCT.md

@@ -0,0 +1,38 @@
+# container/container-libs
+
+This repository is a **monorepo** combining several core Go libraries and utilities from the [containers](https://github.com/containers) project.  
+
+It brings together:  
+
+- **[`common`](./common/)** → Shared Go code and configuration used across multiple containers projects.  
+- **[`storage`](./storage/)** → A Go library for managing container images, layers, and containers.  
+- **[`image`](./image/)** → A Go library for interacting with container images and registries.  
+
+These components are used by major container tools such as [Podman](https://github.com/containers/podman), [Buildah](https://github.com/containers/buildah), [CRI-O](https://github.com/cri-o/cri-o), and [Skopeo](https://github.com/containers/skopeo).
+
+
+---
+
+## Building
+
+Each subproject has its own README.md file with more instructions.
+
+## Contributing
+
+We welcome contributions!
+
+See the **[`CONTRIBUTING.md`](CONTRIBUTING.md)**, **[`CONTRIBUTING_GO.md`](CONTRIBUTING_GO.md)** and **[`CONTRIBUTING_RUST.md`](CONTRIBUTING_RUST.md)** files.
+
+## Code of Conduct
+
+See the **[`CODE-OF-CONDUCT.md`](CODE-OF-CONDUCT.md)** file.
+
+## Security and Disclosure Information Policy
+
+See the **[`SECURITY.md`](SECURITY.md)** file.
+
+
+## License
+
+- Apache License 2.0
+- SPDX-License-Identifier: Apache-2.0