Proposal to consolidate core docs in repo

[ThePrez]

I think it would be a good idea to consolidate some of the core documentation to this repository.

Basic layout would be something like:

Overview
Usage concepts
   - Connections are created with AS400 objects
   - Connections consume server-side jobs
   - Native vs non-native
Examples
   - ProgramCall
   - IFS file access
   - JDBC query
   - Apache Camel
Tracing/logging
Advanced topics
   - JGSS programming
   - Usage with DotEnv-Java-IBMi
Further reading

A lot of the documentation can be scraped from other places. The idea is that, at least for now, this isn't the comprehensive documentation, but we'd get all the basics here and grow it over time. For instance, as we get questions via support channels or possible OSS contributors, we can grow the doc as needed.

Thoughts?