This MR adds the ability to sort discussions by file name, rather than just by date.
This is an optional configuration that can be passed in on startup. The MR also introduces a test suite for the Lua code that runs through Neovim, so that the plugin can be fully tested with required dependencies and APIs.
Major props to @johnybx for the hard work on this change!
This MR adds a Lua test suite to the project, run via busted, and introduces tests for a number of the utility functions. Subsequent work will have to be done to test functions that use the `vim.api` scope and external packages to the plugin.
