Type Annotations

- Add type annotations: [type] statement
- Add type definitions: [[name] type], [[name] := statement]
- Add type annotations example (08)
- add Quickstart.md, reference it from README

README.md

@@ -3,6 +3,9 @@
 Mers is a high-level programming language.
 It is designed to be safe (it doesn't crash at runtime) and as simple as possible.
 
+See also:
+[Quickstart](Quickstart.md),
+
 ## what makes it special
 
 ### Simplicity