Add createLibraryAsync() for async creation

This new function is a just a convenience wrapper around createLibrary(). Instead of immediately returning the library, it waits until the library is initialized.

Author: flekschas

CHANGELOG.md

@@ -1,6 +1,12 @@
 ## Next
 
-_[Changes since v0.9.1](https://github.com/flekschas/piling.js/compare/v0.9.1...master)_
+_[Changes since v0.9.1](https://github.com/flekschas/piling.js/compare/v0.10.0...master)_
+
+## v0.10.0
+
+- Added `createLibraryAsync()` to automatically wait until piling is fully initialized. The function takes as input the same parameters as `createLibrary()`.
+
+_[Changes since v0.9.0](https://github.com/flekschas/piling.js/compare/v0.9.1...v0.10.0)_
 
 ## v0.9.1
 

DOCS.md

@@ -292,6 +292,12 @@ An array of objects with one required property `src` and other optional user-def
 
 **Returns:** a new piling instance.
 
+### createLibraryAsync(_domElement_, _initialProperties_)
+
+**Arguments:** Same as [`createLibrary()`](#createlibrarydomelement-initialproperties).
+
+**Returns:** a promise resolving to the new piling instance once the library was initialized.
+
 ### createLibraryFromState(_domElement_, _initialProperties_, _options_)
 
 **Arguments:**