src/Tools/Demo/README.md

moved lemma

# Demo: Isabelle system component and Isabelle/Scala tool

This directory constitutes an Isabelle system component. It defines an
Isabelle/Scala tool that is available via the command-line as "isabelle demo".

See also "isabelle doc system" on "isabelle components -u" to register system
components in user-space.

NOTE: User-defined components should chose a name prefix that is unlikely to
clash with existing tools (or other user tools).