ECN3 2023

ECN3 geometry with 2023 updates, ready for new background productions for the proposal.

What's Changed

• SND Geometry for Muon Magnetic Spectrometer studies in SHiP by @antonioiuliano2 in #421
• Update Dockerfile for new shipdist by @olantwin in #410
• Reducing transverse size magnetic spectrometer by @antonioiuliano2 in #425
• Fix out of date shebang by @olantwin in #426
• Fix typos in shipVertex error messages. by @olantwin in #427
• Change of magnetic field and SND wall numbers in geometry options by @antonioiuliano2 in #432
• Remove obsolete code by @olantwin in #27
• Update README and add TOC by @olantwin in #434
• Remove unused variable by @olantwin in #440
• ECN3 v2023 by @olantwin in #420

Full Changelog: ECN3_2022...ECN3_2023