Rework the flow of the check-cfg blog post with latest updates

Author: Urgau

posts/2024-05-06-check-cfg.md

@@ -52,25 +52,25 @@ fn win() {}
 
 ![cargo-check](../../../../images/2024-05-06-check-cfg/cargo-check.svg)
 
-## Expecting static cfgs
+## Expecting custom cfgs
 
 *UPDATE: This section was added with the release of nightly-2024-05-19.*
 
-Some crates might use cfgs, like `loom`, `fuzzing` which are always statically known at compile time. For those cases, Cargo provides via the `[lints]` table a way to statically declare those cfgs as expected.
+> In Cargo point-of-view: a custom cfg is one that is neither defined by `rustc` nor by a Cargo feature. Think of `tokio_unstable`, `has_foo`, ... but not `feature = "lasers"`, `unix` or `debug_assertions`
+
+Some crates might use custom cfgs, like `loom`, `fuzzing` or `tokio_unstable` that they expected from the environment (`RUSTFLAGS` or other means) and which are always statically known at compile time. For those cases, Cargo provides via the `[lints]` table a way to statically declare those cfgs as expected.
 
-It is done through the special `check-cfg` config under `[lints.rust.unexpected_cfgs]`:
+Defining those custom cfgs as expected is done through the special `check-cfg` config under `[lints.rust.unexpected_cfgs]`:
 
 *`Cargo.toml`*
 ```toml
 [lints.rust]
 unexpected_cfgs = { level = "warn", check-cfg = ['cfg(loom)', 'cfg(fuzzing)'] }
 ```
 
-## Custom cfgs and build scripts
-
-> In Cargo point-of-view: a custom cfg is one that is neither defined by `rustc` nor by a Cargo feature. Think of `tokio_unstable`, `has_foo`, ... but not `feature = "lasers"`, `unix` or `debug_assertions`
+## Custom cfgs in build scripts
 
-Some crates use custom cfgs that they either expected from the environment (`RUSTFLAGS`or other means) or is enabled by some logic in the crate `build.rs`. For those crates Cargo provides a new instruction: [`cargo::rustc-check-cfg`](https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg)[^2] (or `cargo:rustc-check-cfg` for older Cargo version).
+On the other hand some crates use custom cfgs that are enabled by some logic in the crate `build.rs`. For those crates Cargo provides a new instruction: [`cargo::rustc-check-cfg`](https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg)[^2] (or `cargo:rustc-check-cfg` for older Cargo version).
 
 [^2]: `cargo::rustc-check-cfg` will start working in Rust 1.80 (or nightly-2024-05-05). From Rust 1.77 to Rust 1.79 *(inclusive)* it is silently ignored. In Rust 1.76 and below a warning is emitted when used without the unstable Cargo flag `-Zcheck-cfg`.