added link to TOAR and new section

README.md

@@ -3,7 +3,7 @@ TOAR Gridding Tool
 
 # About 
 
-The TOARgridding projects data from the TOAD database () onto a grid. 
+The TOARgridding projects data from the TOAD database (https://toar-data.fz-juelich.de/) onto a grid. 
 The stations within one cell of the grid are averaged. 
 
 The tool handels the request to the database over the REST API and the subsequent processing.
@@ -11,6 +11,8 @@ The results are provided as xarray objects for subsequent processing by the user
 
 This project is a beta with some basic functionalities. 
 
+# Requirements
+
 # Installation
 
 Move to the folder you want to create download this project to.
@@ -40,5 +42,6 @@ The first supported grid is the Cartesian grid.
 
 # Supported Variables
 
+at the moment only a limited number of variables from the TOAR database is supported.