Update README

Author: willcrichton

README.md

@@ -11,7 +11,7 @@
 The Rust compiler's interface is not stable, so the only sensible way to develop a Rust compiler plugin is by pinning to a specific nightly. Each version of `rustc_plugin` is pinned to one nightly, and you *have* to use the same nightly version that we do. Therefore each release of `rustc_plugin` has a semantic version number (e.g. `0.1.0`) and the nightly version is added as a prerelease label (e.g. `-nightly-2023-08-25`). You can add a dependency to your `Cargo.toml` like this:
 
 ```toml
-rustc_plugin = "=0.12.0-nightly-2024-12-15"
+rustc_plugin = "=0.13.0-nightly-2025-03-03"
 ```
 
 We will treat a change to the nightly version as a breaking change, so the semantic version will be correspondingly updated as a breaking update.
@@ -44,6 +44,7 @@ The `rustc_plugin` framework is responsible for marshalling arguments from the t
 
 Normally, Rust libraries have a [minimum supported Rust version][msrv] because they promise to not use any breaking features implemented after that version. Rust compiler plugins are the opposite — they have a **maximum** supported Rust version (MaxSRV). A compiler plugin cannot analyze programs that use features implemented after the release date of the plugin's toolchain. The MaxSRV for every version of `rustc_plugin` is listed below:
 
+* v0.13 (`nightly-2023-03-02`) - rustc 1.86
 * v0.12 (`nightly-2024-12-15`) - rustc 1.84
 * v0.11 (`nightly-2024-12-01`) - rustc 1.84
 * v0.10 (`nightly-2024-05-20`) - rustc 1.79
@@ -59,6 +60,6 @@ Normally, Rust libraries have a [minimum supported Rust version][msrv] because t
 [Argus]: https://github.com/cognitive-engineering-lab/argus
 [Clippy]: https://github.com/rust-lang/rust-clippy
 [example]: https://github.com/cognitive-engineering-lab/rustc_plugin/tree/main/crates/rustc_plugin/examples/print-all-items
-[docs]: https://cognitive-engineering-lab.github.io/rustc_plugin/v0.12.0-nightly-2024-12-15/rustc_plugin/
-[docs-utils]: https://cognitive-engineering-lab.github.io/rustc_plugin/v0.12.0-nightly-2024-12-15/rustc_utils/
+[docs]: https://cognitive-engineering-lab.github.io/rustc_plugin/v0.13.0-nightly-2025-03-03/rustc_plugin/
+[docs-utils]: https://cognitive-engineering-lab.github.io/rustc_plugin/v0.13.0-nightly-2025-03-03/rustc_utils/
 [msrv]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field