support newlines in responses.md

Author: m-vdb

rasa/nlu/training_data/formats/markdown_nlg.py

@@ -54,6 +54,8 @@ def process_lines(lines: List[Text]) -> Dict[Text, List[Text]]:
 
                     # utterance might have '-' itself, so joining them back if any
                     utterance = "-".join(line.split("- ")[1:])
+                    # utterance might contain escaped newlines that we want to unescape
+                    utterance = utterance.replace("\\n", "\n")
                     story_bot_utterances.append(utterance)
 
                 elif line.startswith("*"):

tests/nlu/training_data/test_markdown_nlg.py

@@ -0,0 +1,13 @@
+from rasa.nlu.training_data.formats import NLGMarkdownReader
+
+
+def test_markdownnlg_read_newlines():
+    md = """
+## Ask something
+* faq/ask_something
+  - Super answer in 2\\nlines
+    """
+    reader = NLGMarkdownReader()
+    result = reader.reads(md)
+
+    assert result.nlg_stories == {"faq/ask_something": ["Super answer in 2\nlines"]}