ecdsa 0.18.0

New features:

• Support for EdDSA (Ed25519, Ed448) signature creation and verification.
• Support for Ed25519 and Ed448 in PKCS#8 and public key files.
• Support for point precomputation for EdDSA.

New API:

• CurveEdTw class to represent the Twisted Edwards curve parameters.
• PointEdwards class to represent points on Twisted Edwards curve and
  provide point arithmetic on it.
• curve_by_name in curves module to get a Curve object by providing curve
  name.

Bug fix:

• Accept private EdDSA keys that include public key in the ASN.1 structure.
• Fix incompatibility with Python 3.3 in handling of memoryviews of empty
  strings.
• Make the VerifyingKey encoded with explicit parameters use the same
  kind of point encoding for public key and curve generator.
• Better handling of malformed curve parameters (as in CVE-2022-0778);
  make python-ecdsa raise MalformedPointError instead of AssertionError.

Doc fix:

• Publish the documentation on https://ecdsa.readthedocs.io/,
  include explanation of basics of handling of ECC data formats and how to use
  the library for elliptic curve arithmetic.
• Make object names more consistent, make them into hyperlinks on the
  readthedocs documentation.
• Make security note more explicit (Ian Rodney)
• Fix the explicit vs named_curve confusion in VerifyingKey docs.

Maintenance:

• Fix few typos (thanks to Tim Gates and Kian Meng Ang).
• Updated black version; slight changes to formatting
• Include interoperability tests for Ed25519 and Ed448 with OpenSSL.