Overhall where installation files are kept for CIL-Demos

[lauramurgatroyd]

Description

• [ ] https://github.com/TomographicImaging/CIL-User-Showcase/issues/20
• [ ] https://github.com/TomographicImaging/CIL-Demos/issues/193
• [ ] https://github.com/TomographicImaging/CIL/issues/1962
• [ ] https://github.com/TomographicImaging/CIL/issues/1963
• [ ] https://github.com/TomographicImaging/CIL/issues/1964

Environment

import cil, sys
print(cil.version.version, cil.version.commit_hash, sys.version, sys.platform)

[casperdcl]

related: #2102 /CC @hrobarts