v0.0.4

• BREAKING: Use logical keys instead of physical keys. Now the characters in key sequence are case-sensitive. For example, logical key A means typing "A" and "Shift" physical keys and it is distinguished from a (only typing "A"). Along with this change, Shift modifier key was removed.
• BREAKING: Rename KeybindDispatcher::trigger to KeybindDispatcher::dispatch.
• Implement FromIterator<Keybind<A>> for KeybindDispatcher<A> to constructor a dispatcher instance from a list of key bindings easily.
• Implement Deref<Target=[KeyBind]> for Keybinds and implement KeybindDispatcher::keybinds getter method.
• Add API document for all optional features.
• Add minimal and serde examples.