Apply dedent to descriptions (#416) (#464)

src/drf_yasg/utils.py

@@ -1,6 +1,7 @@
 import inspect
 import logging
 import sys
+import textwrap
 from collections import OrderedDict
 from decimal import Decimal
 
@@ -438,6 +439,9 @@ def force_real_str(s, encoding='utf-8', strings_only=False, errors='strict'):
         if type(s) != str:
             s = '' + s
 
+        # Remove common indentation to get the correct Markdown rendering
+        s = textwrap.dedent(s)
+
     return s