1.0 release and roadmaps

[adamhathcock]

I'm thinking, after decades, I should do a 1.0 release and follow proper semver as I now have assistance (from LLMs).

Async as resulted in a lot of duplication but it cannot be helped as I want to be "async all the way" to Streams.

Biggest milestone for 1.0: stability around Async.

• Async works (as best as I can test)
• Stable async API.

1.x release

• mark sync API as obsolete (at some point in the future)

2.0

• remove sync code.

[adamhathcock]

maybe sync code won't be deprecated

[adamhathcock]

I think the big API changes are done as of https://www.nuget.org/packages/SharpCompress/0.45.0-beta.400