title: GenesisConfig presets for runtime

doc:
  - audience: Runtime Dev
    description: |
        The runtime now can provide a number of predefined presets of `RuntimeGenesisConfig` struct. This presets are intended to be used in different deployments, e.g.: `local`, `staging`, etc, and should be included into the corresponding chain-specs.
        Having `GenesisConfig` presets in runtime allows to fully decouple node from runtime types (the problem is described in #1984).

        Summary of changes:
        - The `GenesisBuilder` API was adjusted to enable this functionality,
        - (Breaking change) Old `create_default_config` method was removed, `build_config` was renamed to `build_state`. As a consequence a node won't be able to interact with genesis config for older runtimes. The cleanup was made for sake of API simplicity. 

  - audience: Node Dev
    description: |
        The `ChainSpecBuilder` is extended with `with_genesis_config_preset_name` method which allows to build chain-spec using named preset provided by the runtime. 

crates:
  - name: sp-genesis-builder
    bump: minor
  - name: staging-chain-spec-builder
    bump: major
  - name: sc-chain-spec
    bump: major