- template01, provision.sh: add crontab and set it as the background jobs execution agent ...

- template02, provision.sh: add apt install for nextcloud-office-brand
- template05, Vagrantfile: standardize
- how-to: How-to-Setup-Nc-Env-in-Ubuntu-Desktop.md: update vagrant installation instructions

apply some adjustments on Readme.md and provision.sh

initial commit