[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

CHANGELOG.md

@@ -1586,6 +1586,7 @@ raw template
 {%- endblock in_prompt -%}
     """
 
+
 exporter_attr = AttrExporter()
 output_attr, _ = exporter_attr.from_notebook_node(nb)
 assert "raw template" in output_attr

nbconvert/exporters/slides.py

@@ -190,33 +190,33 @@ def _reveal_url_prefix_default(self):
     ).tag(config=True)
 
     reveal_overlay = Unicode(
-                             "",
-                             help="""
+        "",
+        help="""
                              Optional text or html overlay.
                              If this is set then reveal_header, reveal_footer and reveal_backimage are ignored.
                              """,
-                         ).tag(config=True)
+    ).tag(config=True)
 
     reveal_header = Unicode(
-                             "",
-                             help="""
+        "",
+        help="""
                              Optional header to display above slides.
                              """,
-                         ).tag(config=True)
+    ).tag(config=True)
 
     reveal_backimage = Unicode(
-                             "",
-                             help="""
+        "",
+        help="""
                              Optional background image to display behind the slides.
                              """,
-                         ).tag(config=True)
+    ).tag(config=True)
 
     reveal_footer = Unicode(
-                             "",
-                             help="""
+        "",
+        help="""
                              Optional footer to display below slides.
                              """,
-                         ).tag(config=True)
+    ).tag(config=True)
 
     font_awesome_url = Unicode(
         "https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.css",