TimML version 6.4.1

What's Changed (6.4.1)

• Some minor documentation updates by @dbrakenhoff in #109

What's Changed (6.4.0)

• Pull new docs into dev by @dbrakenhoff in #98
• Add 3D and Maq versions of BuildingPit and LeakyBuildingPit by @dbrakenhoff in #97
• return intnormflux per layer and line segment by @dbrakenhoff in #101
• Improve docs by @dbrakenhoff in #104
• Release v6.4.0 by @dbrakenhoff in #108

Full Changelog: v6.4.0...v6.4.1
Full Changelog: v6.3.0...v6.4.0