added content to __init__

structures/__init__.py

@@ -0,0 +1,14 @@
+from embedding import Embedding
+from lexeme import Lexeme
+from word import Word
+from symbol import Symbol
+from phrase import Phrase
+
+
+__all__ = [
+    "Embedding",
+    "Lexeme",
+    "Word",
+    "Symbol",
+    "Phrase",
+]