compatibility with newer sphinx versions

src/sphinx_sleekcat_theme/__init__.py

@@ -1,12 +1,14 @@
 import os
 from sphinx.domains import python as pdom
+from sphinx import addnodes
+from docutils import nodes
 
 __version__ = "0.1.0"
 
 
 class GAttributePyAttribute(pdom.PyAttribute):
     def get_signature_prefix(self, sig):
-        return u'\u2666 '
+        return [nodes.Text(u'\u2666'), addnodes.desc_sig_space()]
 
 
 pdom.PythonDomain.object_types['gattribute'] = pdom.ObjType(