Use @generated in files to follow rustfmt

[atezet]

Changes

Generated Rust files should include @generated in the first few lines. See https://github.com/rust-lang/rustfmt/blob/master/Configurations.md#format_generated_files

Checklist

• An issue to be fixed by this PR is listed above.
• [-] New tests are added to ensure new features are working. Please refer to this page to see how to add a test.
• ./frb_internal precommit --mode slow (or fast) is run (it internal runs code generator, does auto formatting, etc).
• [-] If this PR adds/changes features, documentations (in the ./website folder) are updated.
• CI is passing. Please refer to this page to see how to solve a failed CI.

Remark for PR creator

• ./frb_internal --help shows utilities for development.
• If fzyzcjy does not reply for a few days, maybe he just did not see it, so please ping him.

[welcome]

Hi! Thanks for opening this pull request! 😄

[fzyzcjy]

Good job! Ready to merge after CI is green :)

For this simple PR, you can also manually copy and apply the CI failures.
Also, you may want to change things in the template https://github.com/fzyzcjy/flutter_rust_bridge/tree/master/frb_codegen/assets/integration_template

[fzyzcjy]

(For the last errors, I guess also just copy-paste and execute that patch. Looks like a spacing error)

[atezet]

Thanks! My editor removed some trailing whitespace. I'm not sure exactly why the trailing whitespace is generated, otherwise I'd prevent that instead, but I couldn't figure it out.

[fzyzcjy]

You are welcome!

I'm not sure exactly why the trailing whitespace is generated

I guess it is because rust formatter does not auto remove it (kind of shortcoming I guess)...

[atezet]

Oops, reverted a bit too much!

[welcome]

Hi! Congrats on merging your first pull request! 🎉

[fzyzcjy]

@all-contributors please add @atezet for code

[allcontributors]

@fzyzcjy

I've put up a pull request to add @atezet! 🎉