Force POSIX '\n' line endings in output on all platforms (#109)

Fixes #108.

Author: dbarnett

vimdoc/output.py

@@ -25,7 +25,9 @@ def Filename(self):
 
   def Write(self):
     filename = os.path.join(self.docdir, self.Filename())
-    with io.open(filename, 'w', encoding='utf-8') as self.file:
+    # Output POSIX line endings for portable output that can be published.
+    # They are displayed properly in vim on all platforms.
+    with io.open(filename, 'w', encoding='utf-8', newline='\n') as self.file:
       self.WriteHeader()
       self.WriteTableOfContents()
       for chunk in self.module.Chunks():