Write Individual READMEs for each Submodule

Elypiai has many sub-modules and this continues to increase over time.

We should write individual READMEs for each submodule so it's obvious to each user how to use the respective library rather than having to infer the information from a generic README.

This will allow us to create a quick-start for every module without cluttering the main one in the repository.

If we do this, we may want to replace our bullet point list on the main README with a table, so we can link to the website, docs, README, and possibly denote any information like if it requires authentication or billing information.