Docs: Fix link to source for class properties

The property has setters and getters. Link to the getter if it's available. This adds line numbers to the source link for properties.

Fixes #2401

docs/source/conf.py

@@ -360,6 +360,9 @@ def linkcode_resolve(domain, info):
     else:
         filename = info['module'].replace('.', '/') + '.py'
 
+        if isinstance(val, property):
+            val = val.fget
+
         if isinstance(val, (types.ModuleType, types.MethodType, types.FunctionType, types.TracebackType, types.FrameType, types.CodeType) + six.class_types):
             try:
                 lines, first = inspect.getsourcelines(val)