Release v0.4.1

[jonathanpwang]

In the future we will not squash merge so as to maintain history.

Bug Fixes

• https://github.com/axiom-crypto/halo2-lib/pull/224

Other PRs

• https://github.com/axiom-crypto/halo2-lib/pull/218
• https://github.com/axiom-crypto/halo2-lib/pull/231
• https://github.com/axiom-crypto/halo2-lib/pull/232
• https://github.com/axiom-crypto/halo2-lib/pull/227
• https://github.com/axiom-crypto/halo2-lib/pull/235
• https://github.com/axiom-crypto/halo2-lib/pull/237
• https://github.com/axiom-crypto/halo2-lib/pull/242