ngx-export-0.2.5.1: Changelog.md

### 0.2.5.1

- added signatures for type-checkers and exporters to prevent warnings when
  reifying in a user code with *-Wmissing-signatures* or *-Wall* enabled.

### 0.2.5.0

- added a synchronous handler in IO Monad exported with *ngxExportIOYY*.