The most up to date documentation can be found in Fixits help:
:help fixit.txt
A Neovim plugin to handle basic tasks in a code file.
Via your favorite package manager, for example Packer:
use 'dubgeiser/fixit.nvim'
After Fixit is installed, you need to set it up:
require("fixit.nvim").setup()
Add 'FIXME', 'XXX' and 'TODO' in a code comment, followed by some text.
Run :Fixit to show the tasks in qflist with the text following the token.
Navigate qflist to jump to the corresponding place in the code file.