Add README to bevy_reflect_compile_fail_tests

Author: MrGVSV

crates/bevy_reflect_compile_fail_tests/README.md

@@ -0,0 +1,7 @@
+# Compile fail tests for bevy_reflect
+
+This crate is separate from `bevy_reflect` and not part of the Bevy workspace in order to not fail `crater` tests for 
+Bevy.
+The tests assert on the exact compiler errors and can easily fail for new Rust versions due to updated compiler errors (e.g. changes in spans).
+
+The `CI` workflow executes these tests on the stable rust toolchain (see [tools/ci](../../tools/ci/src/main.rs)).

tools/ci/src/main.rs

@@ -100,7 +100,7 @@ fn main() {
         {
             // Reflect Compile Fail Tests
             // Run tests (they do not get executed with the workspace tests)
-            // - See crates/bevy_ecs_compile_fail_tests/README.md
+            // - See crates/bevy_reflect_compile_fail_tests/README.md
             let _subdir = sh.push_dir("crates/bevy_reflect_compile_fail_tests");
             cmd!(sh, "cargo test --target-dir ../../target")
                 .run()