There are many addons like this, but this addon is mine.
Slashcommand for reloadui
To add a new slashcommand, just add SLASH_RELOAD4 = "/<InputNameHere>" at the end, if you add more remember to change the 4 to 5 and so on.
If you need help just post a comment.
Before any comments about this, not everyone knows lua, not everyone knows how to do this thats why i made it, making it simple so that people can download it and maybe see what it does and building their own stuff from it.