Release 0.2.0

[uncomputable]

First release of rust-simplicity. Releases will make it easier to use rust-simplicity inside other projects such as elements-miniscript.

[uncomputable]

Depends on #198 and #199.

[uncomputable]

@apoelstra Let's merge the release unless you see remaining roadblocks

[RCasatta]

I think some mandatory fields in the Cargo.toml are missing such as description and documentation https://doc.rust-lang.org/cargo/reference/publishing.html#before-publishing-a-new-crate.

it can be tried out using cargo publish --dry-run

[apoelstra]

On my end there are just warnings @RCasatta. I think we're ok.

[apoelstra]

@uncomputable could you squash these three commits? (Or at least the last two; the middle one does not compile.)

[uncomputable]

I squashed so each commit compiles.

I added the missing Cargo fields so cargo publish doesn't emit any warnings. Thank you @RCasatta for providing the command for dry runs!

I added the missing license to the sys crate. There were missing or long license headers, which I resolved. These changes belong to a separate PR, strictly speaking, but I feel like merging quickly :)

[apoelstra]

We have a nice symmetry now with our workspaces being simplicity-lang, simplicity-sys and simplicity-fuzz :)

[apoelstra]

I'm getting a bunch of clippy warnings, which maybe showed up since the edition-2021 change, but we can fix those in a followup PR.

[uncomputable]

Unintended naming symmetry, but I like it, too

[apoelstra]

Tagged and published.

[uncomputable]

Awesome. Cheers to the release 🎉