ManualDi Unity3d v2.1.0

fix: Update SkipDisposable remnants in the codebase

feat: Bump version to 2.1.0

fix: ManualDI.Sync still had the legacy DontDispose method that was renamed to SkipDisposable

feat: Update README with section about ResolveInstance

feat(#67): Installers can now user ResolveInstance to resolve Instances during installation on ManualDi.Sync
This functionality is a great way to access data on installers and conditionally construct the Bindings that end up composing the object graph

feat: Optimize ManualDI.Sync Building speed. Also optimize FromInstance not allocating an unnecesary delegate
This will unify how ManualDi.Async and ManualDi.Sync works in terms of type safety for bindings
This comes at the cost of a type safe API for the Inject, Initialize and Dispose calls that are done manually
This is a concession that we accept given calling the methods is not something that usually needs to be done

feat(#67): Installers can now user ResolveInstance to resolve Instances during installation on ManualDi.Async
This functionality is a great way to access data on installers and conditionally construct the Bindings that end up composing the object graph

feat: Update README with better sample initial code