Add support for Assembly Language

[Hexman768]

Description

I recently came across a commit to the FastColoredTextBox that adds native Assembly Language support to it. If this commit is not merged to that project, then the modified version of the FastColoredTextBox that this project consumes should be updated with that commit. Here is that Pull Request for reference: https://github.com/PavelTorgashov/FastColoredTextBox/pull/249

Impact

This change would be low impact as the change itself would be made in the FastColoredTextBox fork rather than Notepad# itself.