Update contribution guidelines

- Remove outdated note about CoreFoundation.
- Add scope docs.
- Document `Cargo.modified.toml`.
- Small fixes.

Author: madsmtm

CONTRIBUTING.md

@@ -1,9 +1,20 @@
 # Contributing to `objc2`
 
-Thank you for your interest in contributing! There are many ways to contribute and we appreciate all of them.
+Thank you for your interest in contributing to `objc2`! The project is
+currently run mostly by me, [@madsmtm](https://github.com/madsmtm), but I am
+developing this project for the Rust community, and I am very open to
+contributions.
 
+For small changes, just file a PR. For larger changes, please file an issue
+first, such that we can discuss the implementation plan before you potentially
+waste a bunch of work.
 
-## A note for Windows users
+If you prefer to have a more synchronous and less "formal" discussion, we have
+[a Matrix workspace](https://matrix.to/#/#objc2:matrix.org), feel free to
+discuss implenentation details in the "Developers" room.
+
+
+## Windows users
 
 This repository relies heavily on symlinks, so make sure that your system is
 set up to enable those (see [this StackOverflow answer][so-symlink] for
@@ -14,13 +25,13 @@ details on how to do that).
 
 ## Framework crates
 
-`objc2` uses a custom tool called `header-translator` to generate the framework
-crates. Head over to [the README](./crates/header-translator/README.md) for
-more detailed instructions on how to use this tool, and generate new bindings.
+`objc2` uses a custom tool called `header-translator` to generate the crates
+in `framework-crates/*`. The plan is to eventually upstream this tooling into
+[`bindgen`](https://github.com/rust-lang/rust-bindgen), though doing that will
+be a lengthy process.
 
-Note that crates that use `CoreFoundation`-like functionality is likely to not
-yet be translatable, see [#556](https://github.com/madsmtm/objc2/issues/556)
-for progress on this front.
+Head over to [the README](./crates/header-translator/README.md) for more
+detailed instructions on how to use this tool and generate new bindings.
 
 
 ### `git` submodules
@@ -55,17 +66,29 @@ manpage for [`git-submodule`] for further details on how submodules work.
 
 ### Updating the `git` submodule
 
-When making changes to `header-translator`, you must update the `git`
-submodule manually and push your changes to a fork of `objc2-generated` (you
-do not need to submit a PR to that repo).
+When making changes framework crates, you must update the `git` submodule
+manually and push your changes to a fork of `objc2-generated` (you do not need
+to submit a PR to that repo).
 
 We try to maintain a linear history in that repo, in a fashion such that every
 ref that is ever referenced from the `HEAD` branch in this repository, is
 reachable from the `HEAD` branch that repository. This will probably mean
 you'll have to rebase more often.
 
 If you're confused about this, don't worry too much about it, if you enable
-"Allow edits by maintainers" we can fix it for you.
+"Allow edits by maintainers", we can fix it for you.
+
+
+## Scope
+
+The aim of the project is to map all of Apple's C and Objective-C frameworks,
+in [a manner that is as nice to use as possible][nice-to-use].
+
+Access to Swift-only frameworks or functionality is [out of scope][swift-oos]
+for the time being.
+
+[nice-to-use]: https://github.com/madsmtm/objc2/issues/429
+[swift-oos]: https://github.com/madsmtm/objc2/issues/524
 
 
 ## Licensing

README.md

@@ -3,19 +3,21 @@
 [![License](https://badgen.net/badge/license/MIT/blue)](./LICENSE.txt)
 [![CI](https://github.com/madsmtm/objc2/actions/workflows/ci.yml/badge.svg)](https://github.com/madsmtm/objc2/actions/workflows/ci.yml)
 
-**See [`objc2`] for top-level documentation**, including its [documentation on framework crates]. Also check out [`block2`] and [`dispatch2`].
+**See [`objc2`] for top-level documentation**, including [the documentation on framework crates].
+
+Also check out [`block2`] and [`dispatch2`].
 
 [`objc2`]: https://docs.rs/objc2/
-[documentation on framework crates]: https://docs.rs/objc2/latest/objc2/topics/about_generated/index.html
+[the documentation on framework crates]: https://docs.rs/objc2/latest/objc2/topics/about_generated/index.html
 [`block2`]: https://docs.rs/block2/
 [`dispatch2`]: https://docs.rs/dispatch2/
 
 
-## Contact Us
+## Contact
 
 Always feel free to [open an issue on GitHub](https://github.com/madsmtm/objc2/issues/new/choose) if you find a problem or have any questions.
 
-If you prefer to have a more synchronous and less "formal" discussion, we have [a Matrix workspace](https://matrix.to/#/#objc2:matrix.org), feel free to ask any questions in the "Users" room.
+If you prefer to have a more synchronous and less "formal" discussion, there is [a Matrix workspace](https://matrix.to/#/#objc2:matrix.org), feel free to ask any questions in the "Users" room.
 
 
 ## License

crates/header-translator/README.md

@@ -72,6 +72,12 @@ The `translation-config.toml` file describes various tweaks that we need to do b
 
 However, even if our header translation was perfect, we still need a way to enrich the generated data, since C headers have no way to describe which methods are safe and which are not!
 
+Manual modifications to `Cargo.toml` can be done by adding a
+`Cargo.modified.toml` file, and including the keys that you want modified.
+
+See [objc2-foundation](../../framework-crates/objc2-foundation) for a good
+example of these files at work.
+
 
 ### What is required for a method to be safe?