documentation: README completness, debug ocrd-tool.json

[tboenig]

Please debug your ocrd_tool.json file.
I found an error:

<report valid="false">
  <error>NO ocrd-tool.json</error>
</report>

You can find the ocrd-tool.json documentation: https://ocr-d.github.io/ocrd_tool

Please check your README file and complet them. Your README is fine but look at your file and compare your's with the ideal README file.

# Name of application


## Introduction
...

## Installation
...

## Usage
...

## Testing
...

Thank you very much.

[finkf]

This lib only loosely follows the ocrd-cis cli convention. It is intended to be wrapped by ocrd_cis tools, where the according ocrd-tool.json file lies.

[finkf]

The readme file should be improved, though.