add README for pdf-converter

apps/pdf-converter/docker/README.md

@@ -0,0 +1,37 @@
+
+GROWI PDF Converter Official docker image
+==============================================
+
+[![Node CI for slackbot-proxy](https://github.com/weseek/growi/actions/workflows/ci-pdf-converter.yml/badge.svg)](https://github.com/weseek/growi/actions/workflows/ci-slackbot-proxy.yml) [![docker-pulls](https://img.shields.io/docker/pulls/weseek/growi-pdf-converter.svg)](https://hub.docker.com/r/weseek/growi-pdf-converter/)
+
+
+Supported tags and respective Dockerfile links
+------------------------------------------------
+
+* [`1.0.0`, `latest` (Dockerfile)](https://github.com/weseek/growi/blob/master/apps/pdf-converter/docker/Dockerfile)
+
+
+What is GROWI PDF Converter used for?
+---------------------------------------
+
+GROWI provides a feature that bulk exports pages in PDF format.
+PDF Converter is necessary to convert markdown pages to PDF during that process.
+
+
+Usage
+-----
+
+```bash
+docker run -d weseek/pdf-converter
+```
+
+and go to `http://localhost:3010/` .
+
+### docker-compose
+
+(TBD)
+
+Configuration
+-----------
+
+(TBD)