Try
touch Settings/StaticFiles.hs
It is that particular file because the template haskell code for static files is in that file (in the default scaffolded structure). Touching that file will recompile it and reexecute the template haskell code.
edit: Sorry, I noticed this doesn't answer your question regarding how to develop with the static js/css source files like you do with the files in the templates
folder. Well, you should not have js/css files in your static
folder, please consider moving your .js
/.css
files to the template
folder and use the shakespearian languages if you feel you're actively working on the css and js files.
You only put the js/css files in the static
folder when you've taken a large code base from somewhere else, like the blueprint css framework. See my answer on this question.