Update documentation.

README.md

@@ -1 +1,23 @@
-# docker-rotate-backups
+# docker-rotate-backups
+This repository provides a Docker image that implements [`rotate-backups`](https://pypi.org/project/rotate-backups/).
+
+Using this image you are enabled to instantiate container that runs rotate-backups once on a mounted directory where your backups are stored. Afterwards, the container is stopped and, if desired, removed.
+
+## How to use
+Simply adapt the directory to mount and run the following command in your Docker host:
+```
+docker run --rm \
+-v /path/to/backups:/archive \
+ghcr.io/jan-brinkmann/docker-rotate-backups
+```
+The default schema to preserve and to remove backups is `--daily=7 --weekly=4 --monthly=12 --yearly=always --dry-run`.
+
+## How to customize
+The schema can be customized by means of `ROTATE_BACKUPS_CONFIG`:
+```
+docker run --rm \
+-e ROTATE_BACKUPS_CONFIG="--daily=7 --weekly=4 --monthly=6" \
+-v /path/to/backups:/archive \
+ghcr.io/jan-brinkmann/docker-rotate-backups
+```
+For more information on the synthax and the option of the schema, we refer to the [official `rotate-backups` documentation](https://pypi.org/project/rotate-backups/#command-line).