Add a README to scripts/, indicating that these are not for general use.

scripts/README

@@ -0,0 +1,6 @@
+This directory contains scripts that are (or were once) used to maintain the
+database. Most of them will not work any more, since whatever they did was
+already done. They're included here for reference, should something similar be
+needed again.
+
+Make sure you know what you are doing when running these.

scripts/add-bw-locations.py

@@ -1,4 +1,8 @@
 #!/usr/bin/env python2
+"""
+This is an unmaintained one-shot script, only included in the repo for
+reference.
+"""
 
 from codecs import open
 

scripts/migration-i18n.py

@@ -9,6 +9,9 @@ Creates autoincrement-style IDs when missing
 Sets text language to 9 (en), except when it sets to 1 (jp)
 
 And looks good doing it!
+
+This is an unmaintained one-shot script, only included in the repo for
+reference.
 """
 
 import csv