Add corpus/special.PS1: a static prompt with many special chars
Add demo.sh: a scenario for a screenshot
demo: build a complete home directory
demo: many script improvements
demo: hide machine name from default bash prompt
demo: more technicals details shown (too much?)
demo: use mktemp for the temporary directory
demo: minor refactoring + fix output
demo: check if ./angel-PS1 exists
demo: sleep loop instead of a constant