[WIP] Documentation

[UFOMelkor]

Most of this documentation has been written just be reading the source code of the bundle. So please review carefully.

• Installation
• Event Store configuration
• Repositories
• Reusing PDO Connections from Doctrine
• Plugin registration
• Metadata enricher
• Central projection configuration
• Projection configuration using tags
• Running projections
• Access to projections, read models and projection managers through service locators
• Event Store Bus Bridge
• Configuration reference

This documentation assumes two features that are not added to the bundle yet:

• Using repository classes as service ids (Configuration value of the repositories / Service naming #5, see repository_class configuration option could be replaced with FQCN repository name #32)
• Adding an @ in front of service names (consistent to the service-bus-bundle) (Allow service references with a prefix @ #29, see Allow services to be prefixed with @ #41)

PRs for both features will follow are done.

[codeliner]

Reminder:
configuration example for AggregateStreamStrategy would be nice, because an additional flag for the repository is needed when using this stream stragegy:

The repository can also be configured to create a new stream for each new aggregate instance. You'll need to turn the last constructor parameter oneStreamPerAggregate to true to enable the mode

https://github.com/prooph/event-sourcing/blob/master/docs/repositories.md#event-streams