Pyecs

Changes
* added `Store.get_children_with` and `Entity.get_children_with`

Changes
* added docstrings

Changes

* add `ECController.get_entities`
* removed a lot of _overcaching_, simple lookups don't need the caching overhead...

Changes

* Merged `get_entities_with` and `get_unpacked_entities_with` using proper typing, i.e. `Literal` and `overload`.

Changes

* add `Entity.add_child`

First Github Release

Features
* Entity-Component management
* Adding/Removing Entities
* Adding/Removing Components from Entities
* instant and delayed removal of Entities and Components
* Entity-Component polling
* Getting Entity by uuid
* Getting Component/s by Entity uuid and Component-Type
* Getting Entities by Component-Type/s (yields Entity "proxy" or tuple of requested Components)
* Entity hierarchy