Qldpc

What's Changed
* Combine formatting and linting checks by perlinm in https://github.com/Infleqtion/qLDPC/pull/156
* Add more decoders from `ldpc` and use BP-LSD by default by perlinm in https://github.com/Infleqtion/qLDPC/pull/157
* Add early stopping to `*Code.get_distance_bound` methods by perlinm in https://github.com/Infleqtion/qLDPC/pull/158
* Revert to BP-OSD as the default decoder by perlinm in https://github.com/Infleqtion/qLDPC/pull/159
* Allow stacking many codes by perlinm in https://github.com/Infleqtion/qLDPC/pull/161
* Flatten logical operator arrays (`QuditCode.get_logical_ops()`) into a matrix by perlinm in https://github.com/Infleqtion/qLDPC/pull/163
* Add quantum code concatenation by perlinm in https://github.com/Infleqtion/qLDPC/pull/162
* version bump to 0.0.21 by perlinm in https://github.com/Infleqtion/qLDPC/pull/164


**Full Changelog**: https://github.com/Infleqtion/qLDPC/compare/v0.0.20...v0.0.21

What's Changed
* add gap to external/__init__.py by perlinm in https://github.com/Infleqtion/qLDPC/pull/147
* Clean up example notebooks by perlinm in https://github.com/Infleqtion/qLDPC/pull/149
* Simplify encoding tableau and circuit by perlinm in https://github.com/Infleqtion/qLDPC/pull/150
* Add methods to "stack" codes by perlinm in https://github.com/Infleqtion/qLDPC/pull/148
* Add (brute force) calculation of code distance for QuditCodes by perlinm in https://github.com/Infleqtion/qLDPC/pull/151
* Add code cannonicalization and validation by perlinm in https://github.com/Infleqtion/qLDPC/pull/152
* Add helper functions for qubit placement + layouts in the BBCode by perlinm in https://github.com/Infleqtion/qLDPC/pull/153
* Update ldpc version by perlinm in https://github.com/Infleqtion/qLDPC/pull/154
* version bump to 0.0.20 by perlinm in https://github.com/Infleqtion/qLDPC/pull/155


**Full Changelog**: https://github.com/Infleqtion/qLDPC/compare/v0.0.19...v0.0.20

Biggest highlights
* Add encoding circuits for qubit codes by perlinm in https://github.com/Infleqtion/qLDPC/pull/136
* Add calculation of the automorphism group for classical linear codes by perlinm in https://github.com/Infleqtion/qLDPC/pull/138
* Construct transversal Clifford gates for qubit codes by perlinm in https://github.com/Infleqtion/qLDPC/pull/139
* Find a physical transversal circuit for a logical Clifford, if possible by perlinm in https://github.com/Infleqtion/qLDPC/pull/143

Other changes
* Pin working `ldpc` dependency by dowusu-antwi in https://github.com/Infleqtion/qLDPC/pull/134
* Update to sphinx-autoapi by cdbf1 in https://github.com/Infleqtion/qLDPC/pull/135
* Factor out GAP interface by perlinm in https://github.com/Infleqtion/qLDPC/pull/137
* Clean up interactions between cache and pytest by perlinm in https://github.com/Infleqtion/qLDPC/pull/140
* Upgrade to `ldpc_v2` by perlinm in https://github.com/Infleqtion/qLDPC/pull/141
* version bump to `0.0.19` by perlinm in https://github.com/Infleqtion/qLDPC/pull/145

New Contributors
* dowusu-antwi made their first contribution in https://github.com/Infleqtion/qLDPC/pull/134
* cdbf1 made their first contribution in https://github.com/Infleqtion/qLDPC/pull/135

**Full Changelog**: https://github.com/Infleqtion/qLDPC/compare/v0.0.18...v0.0.19

What's Changed
* Add quasi-cyclic code (QCCode) and factor out bivariate bicycle code (BBCode) by perlinm in https://github.com/Infleqtion/qLDPC/pull/130
* Better interface for identifying "toric layouts" of BBCodes
* Remove conjugated argument from `QuditCode.__init__` methods by perlinm in https://github.com/Infleqtion/qLDPC/pull/131
* Minor bugfixes


**Full Changelog**: https://github.com/Infleqtion/qLDPC/compare/v0.0.17...v0.0.18

Fix a bug with incorrect behavior when GAP is not installed.

What's Changed
* Change convention for logical operators by perlinm in https://github.com/Infleqtion/qLDPC/pull/97
* Add bare-bones documentation by perlinm in https://github.com/Infleqtion/qLDPC/pull/98
* Change conventions for `CSSCode.matrix` by perlinm in https://github.com/Infleqtion/qLDPC/pull/114
* Improved modular coverage by perlinm in https://github.com/Infleqtion/qLDPC/pull/115
* Remove 'script' dependency by perlinm in https://github.com/Infleqtion/qLDPC/pull/124
* Use `ruff` for formatting and linting by perlinm in https://github.com/Infleqtion/qLDPC/pull/126
* Change logical operator format by perlinm in https://github.com/Infleqtion/qLDPC/pull/127
* Protograph bugfixes by perlinm in https://github.com/Infleqtion/qLDPC/pull/128


**Full Changelog**: https://github.com/Infleqtion/qLDPC/compare/v0.0.15...v0.0.16