python docs: link to GRASS GIS project site added

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@71886 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/python/docs/src/index.rst

@@ -3,8 +3,9 @@ GRASS GIS Python library documentation
 
 Python, a widely used general-purpose, high-level programming language 
 provides a powerful scripting interface. Being easy-to-use yet 
-powerful, it enables users to efficiently exploit the capabilities of 
-the GRASS GIS software. Python scripts for GRASS GIS can be written at 
+powerful, it enables users to efficiently exploit the capabilities
+of the [GRASS GIS](https://grass.osgeo.org/) software.
+Python scripts for GRASS GIS can be written at 
 high level (GRASS GIS modules) as well as at low level (GRASS GIS 
 libraries) through a dedicated interface. The graphical user interface 
 and the GRASS GIS Temporal Framework are entirely written in Python.