add docker hub readme

docker/README.md

@@ -0,0 +1,24 @@
+# Supported tags
+
+- latest
+- 0.2
+
+# vnetod
+
+Dotenv state switcher
+
+# Usage
+
+```sh
+docker run --rm -it -v $PWD:/data pleshevskiy/vnetod -f .env.example -o .env staging db:local debug:on
+```
+
+For more details see [the repo](https://git.pleshevski.ru/pleshevskiy/vnetod)
+
+# License
+
+GNU General Public License v3.0 or later
+
+See [COPYING](./COPYING) to see the full text.
+
+[COPYING]: https://git.pleshevski.ru/pleshevskiy/vnetod/src/branch/main/COPYING