main
build: Replace join_paths with the / operator
doc/toolbox-create, doc/toolbox-init-container: Mention /etc/machine-id
doc, cmd: Tweak the wording and error messages for consistency
Drop one "o" and rename the project as "Toolbx"
NEWS, NEWS.old, README.md, doc: Re-align
README.md, doc/toolbox: Mention /run/host