Document the MSRV in CHANGELOG.md (#619)

I think this is probably a useful property of a release to document.

CHANGELOG.md

@@ -13,6 +13,8 @@ You can find its changes [documented below](#020---2024-06-08).
 
 ## [Unreleased]
 
+This release has an [MSRV][] of 1.75.
+
 ### Added
 
 ### Changed
@@ -21,6 +23,8 @@ You can find its changes [documented below](#020---2024-06-08).
 
 ## [0.2.0] - 2024-06-08
 
+This release has an [MSRV][] of 1.75.
+
 ### Added
 
 - Euler spiral based stroke expansion. ([#496] by [@raphlinus])
@@ -95,3 +99,5 @@ You can find its changes [documented below](#020---2024-06-08).
 [Unreleased]: https://github.com/linebender/vello/compare/v0.2.0...HEAD
 [0.2.0]: https://github.com/linebender/vello/compare/v0.1.0...v0.2.0
 [0.1.0]: https://github.com/linebender/vello/releases/tag/v0.1.0
+
+[MSRV]: README.md#minimum-supported-rust-version-msrv

Cargo.toml

@@ -23,7 +23,8 @@ members = [
 version = "0.2.0"
 
 edition = "2021"
-# Keep in sync with RUST_MIN_VER in .github/workflows/ci.yml and with the relevant README.md files.
+# Keep in sync with RUST_MIN_VER in .github/workflows/ci.yml, with the relevant README.md files
+# and with the MSRV in the `Unreleased` section of CHANGELOG.md.
 rust-version = "1.75"
 license = "Apache-2.0 OR MIT"
 repository = "https://github.com/linebender/vello"