Implement hook_help() in .module file

Getting the error in D8.7 and D8.8

Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. It is recommended that you run `composer update` or `composer update <package name>`.
- Required package "zaporylie/composer-drupal-optimizations" is not present in the lock file.
This usually happens when composer files are incorrectly merged or the composer.json file is manually edited.
Read more about correctly resolving merge conflicts https://getcomposer.org/doc/articles/resolving-merge-conflicts.md
and prefer using the "require" command over editing the composer.json file directly https://getcomposer.org/doc/03-cli.md#require-r

Showing the content of the README file in a hook_help() implementation is a bad idea, since the content of that file, like how to install the module, which dependencies that module has, or who are the maintainers, is not relevant information, once the module is installed.

Furthermore, the content of a file cannot be translated, differently from the strings passed to t().