Separate rerankers, splitters and extractors (#85)

knowledgehub/indices/extractors/doc_parsers.py

@@ -0,0 +1,19 @@
+from ..base import DocTransformer, LlamaIndexMixin
+
+
+class BaseDocParser(DocTransformer):
+    ...
+
+
+class TitleExtractor(LlamaIndexMixin, BaseDocParser):
+    def _get_li_class(self):
+        from llama_index.extractors import TitleExtractor
+
+        return TitleExtractor
+
+
+class SummaryExtractor(LlamaIndexMixin, BaseDocParser):
+    def _get_li_class(self):
+        from llama_index.extractors import SummaryExtractor
+
+        return SummaryExtractor