Add docs info (#183)

Added doc shield,  use RTD link for get started

INSTALL.md

@@ -1,3 +1,3 @@
 # Installing PySwip
 
-This content has moved to [PySwip Get Started](https://pyswip.org/get-started.html)
+This content has moved to [PySwip Get Started](https://pyswip.readthedocs.io/en/latest/get_started.html)

README.md

@@ -1,6 +1,8 @@
 <a href="https://pypi.python.org/pypi/pyswip"><img src="https://img.shields.io/pypi/v/pyswip.svg?maxAge=2592&updated=2"></a>
 <img src="https://img.shields.io/github/actions/workflow/status/yuce/pyswip/tests.yaml">
 <a href="https://coveralls.io/github/yuce/pyswip"><img src="https://coveralls.io/repos/github/yuce/pyswip/badge.svg?branch=master"></a>
+<a href="https://pyswip.readthedocs.io/en/latest/"><img src="https://readthedocs.org/projects/pyswip/badge/?version=latest"></a>
+
 
 # PySwip
 
@@ -19,7 +21,7 @@ If you have SWI-Prolog installed, it's just:
 pip install pyswip
 ```
 
-See [Get Started](https://pyswip.org/get-started.html) for detailed instructions.
+See [Get Started](https://pyswip.readthedocs.io/en/latest/get_started.html) for detailed instructions.
 
 ## Introduction