Properly closing all files in Python code

doc/tools/makemd.py

@@ -93,6 +93,8 @@ def make_class_list(class_list, columns):
         s += '\n'
         f.write(s)
 
+    f.close()
+
 
 def dokuize_text(txt):
 
@@ -330,6 +332,8 @@ def make_doku_class(node):
             f.write('\n')
             f.write(dokuize_text(d.text.strip()))
             f.write('\n')
+   
+    f.close()
 
 
 for file in input_list: