Add frequently misspelled UK shops

See also this thread on the talk-gb mailing list:
https://lists.openstreetmap.org/pipermail/talk-gb/2014-December/016922.html
True, quite some name=Thompson objects will not be travel agencies.

On the other hand, name-suggestion-index is not used for automatic renaming, and the canonical index is only used for counting total numbers for ordering purposes, so I think it's not a big risk.

I could drop it, what do the maintainers of name-suggestion-index think of it?