Normally you should not have any problem downloading the dictionary files, even if they cannot be displayed on GitHub. Just click on “View raw” to get the content.
https://raw.githubusercontent.com/jsgonsette/Wizium/master/Dictionaries/Fr_ODS4.txt
Anyway, the structure is very simple and is more related to the example than to the library. It’s just a list of word (e.g ASCII, UTF8) that is loaded by the Python script before to be pushed in the library engine. The strange line you mention is there to ensure that every word is only made of alphabetical letters, removing any other accented character or other odd things: Function re.sub substitutes any first occurence of first argument (regular expression) by the second (empty string).
I hope those explanations make things clearer.
Greetings
