WPF - about dialog and fixes

Added new About dialog with description, credits, license...
Added icon.
Some fixes.

v0.10 - First beta

added proper logging

WPF release 0.9

Fixed problem with missing chapters.

WPF release

v0.8-alpha

Adding publish script.

AudibleBookmarks v0.7-alpha

Adding publish script.

AudibleBookmarks v0.6-alpha

Adding publish script.

AudibleBookmarks v0.5-alpha

Adding publish script.

Cross-platform release

This release is based on .net core (.net standard 2.0) and AvaloniaUI.
Self-containing (contains whole .net core 2) release was published for every platform.

Third alpha

All main features are implemented including export template.

Second alpha

More stable than first one. Has auto search for library.