[docs] minor code refactoring

docs/source/_ext/utils.py

@@ -0,0 +1,17 @@
+from myst_parser.docutils_ import Parser
+from myst_parser.mdit_to_docutils.base import make_document
+
+
+def md_to_docutils(text):
+    parser = Parser()
+    doc = make_document(parser_cls=Parser)
+    parser.parse(text, doc)
+    return doc
+
+
+def get_link_key(node):
+    link_keys = ['uri', 'refuri', 'refname']
+    for key in link_keys:
+        if key in node.attributes.keys():
+            return key
+    return None