Replace warning with semantic versioning notice

The warning in the README is arguably unnecessary and causing more
confusion than necessary. For one, it references [Semantic
versioning](https://semver.org/) but that differs from Cargo's treatment
of versions in subtle ways (in that it declares a free-for-all for
anything below 1.0).
Let's just state that we follow Cargo's semantic versioning rules and
leave it at that.

Signed-off-by: Daniel Müller <[email protected]>

Author: d-e-s-o

libbpf-cargo/README.md

@@ -1,10 +1,6 @@
 ![CI](https://github.com/libbpf/libbpf-rs/workflows/Rust/badge.svg?branch=master)
 [![rustc](https://img.shields.io/badge/rustc-1.63+-blue.svg)](https://blog.rust-lang.org/2022/08/11/Rust-1.63.0.html)
 
-WARNING: The API is not stable and is subject to breakage. Any breakage will
-include a minor version bump pre-1.0 and a major version bump post-1.0.
-[Semantic versioning](https://semver.org/) will be followed post-1.0 release.
-
 # libbpf-cargo
 
 [![crates.io badge](https://img.shields.io/crates/v/libbpf-cargo.svg)](https://crates.io/crates/libbpf-cargo)
@@ -21,7 +17,11 @@ libbpf-cargo = "0.20"
 
 See [full documentation here](https://docs.rs/libbpf-cargo).
 
+This crate adheres to Cargo's [semantic versioning rules][cargo-semver].
+
 ## Contributing
 
 We welcome all contributions! Please see the [contributor's
 guide](../CONTRIBUTING.md) for more information.
+
+[cargo-semver]: https://doc.rust-lang.org/cargo/reference/resolver.html#semver-compatibility

libbpf-rs/README.md

@@ -1,10 +1,6 @@
 ![CI](https://github.com/libbpf/libbpf-rs/workflows/Rust/badge.svg?branch=master)
 [![rustc](https://img.shields.io/badge/rustc-1.63+-blue.svg)](https://blog.rust-lang.org/2022/08/11/Rust-1.63.0.html)
 
-WARNING: The API is not stable and is subject to breakage. Any breakage will
-include a minor version bump pre-1.0 and a major version bump post-1.0.
-[Semantic versioning](https://semver.org/) will be followed post-1.0 release.
-
 # libbpf-rs
 
 [![crates.io badge](https://img.shields.io/crates/v/libbpf-rs.svg)](https://crates.io/crates/libbpf-rs)
@@ -21,7 +17,11 @@ libbpf-rs = "0.20"
 
 See [full documentation here](https://docs.rs/libbpf-rs).
 
+This crate adheres to Cargo's [semantic versioning rules][cargo-semver].
+
 ## Contributing
 
 We welcome all contributions! Please see the [contributor's
 guide](../CONTRIBUTING.md) for more information.
+
+[cargo-semver]: https://doc.rust-lang.org/cargo/reference/resolver.html#semver-compatibility