Matchmaps

This release adds `matchmaps.mr`, a utility for making difference maps between inputs in different spacegroups.

`matchmaps` now contains the three core utilities it will need:

- `matchmaps`, for standard "not quite isomorphous" inputs
- `matchmaps.mr`, for inputs where molecular replacement is necessary
- `matchmaps.ncs`, for making internal difference maps across non-crystallographic symmetry

Introducing `matchmaps.ncs`

This release introduces `matchmaps.ncs`, a new command-line utility for computing internal difference maps between NCS-related molecules.

What's Changed
* Updates by dennisbrookner in https://github.com/dennisbrookner/matchmaps/pull/7
* Functional `matchmaps.ncs` and more by dennisbrookner in https://github.com/dennisbrookner/matchmaps/pull/8


**Full Changelog**: https://github.com/dennisbrookner/matchmaps/compare/v0.1.4...v0.2.0

Multiple rigid-body groups can now be specified via the `--rbr-selections`/`-r` flag, which replaces the `--selection` flag. These groups will be allowed to move separately in rigid-body refinement and will be aligned and subtracted separately in real space.

The deprecation of the `--selection` flag also means temporary deprecation of specifying special-position atoms to exclude. This feature was never well-tested. It should be reimplemented in the future.

What's Changed
* ci(pre-commit.ci): autoupdate by pre-commit-ci in https://github.com/dennisbrookner/matchmaps/pull/4
* Support for multiple rigid-body selections by dennisbrookner in https://github.com/dennisbrookner/matchmaps/pull/6

New Contributors
* pre-commit-ci made their first contribution in https://github.com/dennisbrookner/matchmaps/pull/4

**Full Changelog**: https://github.com/dennisbrookner/matchmaps/compare/v0.1.3...v0.1.4

What's Changed
* Scaling by dennisbrookner in https://github.com/dennisbrookner/matchmaps/pull/1

**Full Changelog**: https://github.com/dennisbrookner/matchmaps/compare/v0.1.1...v0.1.3