docbook: fixed the xslt output (remove DOCTYPE)

The doctype caused errors in the parsing of the html,
as it apears inside the template.
Adjusted this and pretty printed the string for readability

diff --git a/treecutter/docbook.py b/treecutter/docbook.py
index 1e39a9867ca7970a746d66441f8503bf7848b05d..ee310549c1713ae67ad73583e0e5118f7cc091fe 100644 (file)
--- a/treecutter/docbook.py
+++ b/treecutter/docbook.py
@@ -240,7 +240,13 @@ class Docbook:
 
     def xslt(self, transform):
         """XSLT transform"""
-        return etree.tostring(transform(self._doc))
+        transformed = transform(self._doc)
+        transformed_str = etree.tostring(transformed.getroot(),
+                                         encoding="unicode",
+                                         method="xml", doctype=None,
+                                         pretty_print=True,
+                                         xml_declaration=False))
+        return transformed_str
 
     def clean(self):
         """cleaning xml"""