fix: add dockerfile labels (#16)

that can be used for dependabot

Author: carlossg

Dockerfile

@@ -1,5 +1,8 @@
 FROM python:3-alpine
 
+LABEL org.opencontainers.image.source="https://github.com/commitizen-tools/commitizen"
+LABEL org.opencontainers.image.description="Commitizen is release management tool designed for teams"
+
 WORKDIR /app
 
 # Add dependencies

README.md

@@ -1,6 +1,6 @@
 # commitizen-docker-image
 
-> commitizen now avaialble in docker 💪
+> commitizen now available in docker 💪
 
 ![Docker Pulls](https://img.shields.io/docker/pulls/commitizen/commitizen?style=flat-square)
 ![Docker Image Size (tag)](https://img.shields.io/docker/image-size/commitizen/commitizen/latest?style=flat-square)