Include unprivileged exec folder to execute commands as default user

Include unprivileged exec folder to execute commands as default user allowing the possibility to run commands that need to rely on default user privileges such as copying files to home folder, run ruby gems that do stuff on users home folder, run composer global install, composer global require and many other use cases

Change execute-files.sh to avoid permission denied errors when running unprivileged files
Change docs to express the changes