Simple HTML editor. Virtually all editors have configuration files that they read when they start up. TPU has several. Here is a sample configuration file for EDT and instructions for using it. It will take effect next time you log in.
Most text editors use particularly keypad keys for certain purposes.
Unfortunately, the keys on your keyboard may not be labeled to match the names used in the program. It is usually, but not invariably, the leftmost button in the top row of the numeric keypad. If that fails, press the second to leftmost key on the top row of the numeric keypad. Delete the original after first verifying the copy. As usual, there are a couple of ways.