Package-level declarations

com.quarkdown.core.flavor.base.BaseMarkdownFlavor extension with, in addition:

QuarkdownFlavor lexer factory.

QuarkdownFlavor parser factory. Quarkdown parsing doesn't differ from the base one, as new nodes are generated by the lexer, instead of the parser.

QuarkdownRendererFactory renderer factory.

QuarkdownFlavor tree iterator factory.