[doc] Update README.md (#23)

Author: vityaman

README.md

@@ -2,8 +2,12 @@
 
 LISP-like Simple Language Educational Edition
 made as a final project for ITMO Computer
-Arhitecture course.
+Arhitecture course. It is translated to `Tafka IR`,
+that then is compiled into `Asmik` assembler for the
+`Sleepy VM`.
 
 ## Documentation
 
+- [Language Specification](./doc/lang/spec.md)
+- [Language Grammar](./doc/lang/sleepy.g4)
 - [Developement Guide](./doc/dev.md)