README.md information looks outdated

[Jaxelr]

Skimming at the repo it seems that this information from the README.md is outdated. With your approval, I wanted to submit a PR to reflect the current main branch.

CoseSignTool runs on .NET 7. It depends on the libraries from this package

It looks to be targeting .NET 8.

CoseHandler currently builds on .NET 7 but will be switched to .NET Standard 2.0 soon to match the other libraries.

CoseHandler looks to be already targeting .NET standard 2.0

[ivarprudnikov]

Related PR #116

[achamayou]

The README also states:

This is an alpha release, so there are some planned features that are not yet in the product, and you may encounter some bugs.

Is this still true? The current version (1.6.5) suggests otherwise. @elantiguamsft @JeromySt could you confirm?