I was recently looking for a spell checker add-on for Anki and I found this add-on named (Legacy) Spelling Police™ and here it's GitHub page but the problem is that it needs to feed with user's own dictionaries and that also in BDIC format and after looking on the internet for a long time I can only find dictinaries in .txt format and here is the link for it.

So, now I need a way to convert this .txt format to .bdic format.