Release v0.5.4

What's Changed

• Feat/cell optimise natsort -> exp by @pgleeson in #177
• Towards semi-automated path generation by @sanjayankur31 in #178
• Use natsort to properly sort segments/groups when optimising by @pgleeson in #179
• feat(nml.py): use natsort to properly sort segments/groups when optimising by @sanjayankur31 in #176
• To v0.5.4 by @pgleeson in #180

Full Changelog: v0.5.3...v0.5.4