Update README

Signed-off-by: Kakadu <Kakadu@pm.me>

Author: Kakadu

README.md

@@ -1,6 +1,6 @@
 [![Ostap][1]][2]
 [![License](https://img.shields.io/badge/license-LGPL-blue)](https://github.com/JetBrains-Research/spla/blob/master/LICENSE.md)
-[![API docs](https://img.shields.io/badge/API-documentation-yellowgreen)](https://PLTools.github.io/ostap/api/)
+[![API docs](https://img.shields.io/badge/API-documentation-yellowgreen)](https://pltools.github.io/ostap/api/ostap/index.html)
 
 
 [1]:  https://github.com/PLTools/ostap/actions/workflows/master.yml/badge.svg
@@ -10,4 +10,6 @@
 
 # ostap
 
-asdfasd
+Ostap is a parser-combinator library, armed by Camlp5 syntax extension to write parsers.
+
+Docs: https://pltools.github.io/ostap/api/ostap/index.html