Yep, you can just open those luac files with any text editor. The problem is that they are minified, and the code is hard to read that way, it’s not properly indented, lines are stuck together, there’s no syntax coloring.
That’s why there were things like Lua unminify ( Lua Unminifier/Formatter - Improved ) or unwrp ( Unwrp r22 - A tool to easily extract smod files and decompile luac (now with pretty formatting!) ).
Sublime and Notepad++ offer better syntax coloring, once you told them that the file they opened has Lua syntax.
You could always unminify them, save them as .lua files and then open them with your preferred editor. I usually don’t bother with unminifying because I go directly to the few files / code that I want to check / copy, and then add the new lines or spaces myself.
There are too many lua files in the game to bother unminifying all of them, and knowing that they might change between alphas.