Change docs man page for 1 to 7 (Issue #720)

docs/conf.py

@@ -162,7 +162,7 @@ latex_documents = [
 # (source start file, name, description, authors, manual section).
 man_pages = [
     (master_doc, 'lark', 'Lark Documentation',
-     [author], 1)
+     [author], 7)
 ]