Enhance off-topic names search feature

https://github.com/python-discord/bot/issues/435

This commit is meant to enhance the search feature in three separate,
but related ways:

1. By changing the type annotation of the query to OffTopicName, we
   will use the same character translation table for the query as we
   did when storing the off-topic name, leading to better matches.

2. By adding a membership test, `query in name`, we are better able to
   search for off-topic names using a substring.

3. Given point 1 and point 2, we can increase the cut-off value we use
   for `difflib.get_close_matches` so we reduce the number of matches
   that bear little resemblance to the query in our human eyes.

This commit closes #435

0 files changed, 0 insertions, 0 deletions