How to make a user dictionary from a text file?

I need auto correct for making notes but problem is most of the words are not in english dictionary. But I have a txt file which contain all the words that I want to be in my user dictionary. Is there a way possible to do this?

{"en-GB":["AAA","BBB", "CCC"]}

This is the format in which word I add to dictionary are stored in /.config/Typora/dictionaries/user-dict.json.

What I want is to scan .txt file containing valid word and add all the word which are not in default dictionary to this user dictionary.

EDIT: What I did till now is Extracting all the words with length greater than 5 using

grep -o -w '\w\{5,100\}' word.txt > newlist.txt

And then pasted into en_GB.dic file.

Aborigine/MS
Abraham/M
Abram/MS

Previously it had list of word like this but I don't know why /MS and /M were used? Also there are repeated entrys now if I get the importantance of /MS and /M here, if they are not important then I can remove them and remove repeated words.