Mostly internal change.

PiperOrigin-RevId: 504122619
diff --git a/support/rstd/README.md b/support/rstd/README.md
index 4ff7000..92c8d42 100644
--- a/support/rstd/README.md
+++ b/support/rstd/README.md
@@ -5,6 +5,6 @@
 
 This directory contains C++ libraries that help work with Rust types.  For
 example, `rstd::Char` represents Rust's `char` type (a separate type from
-C++'s `char32_t` is needed to detect certain invalid bit patterns
+C++'s `char32_t` is needed to detect certain invalid bit patterns that
 result in Undefined Behavior in Rust;  additionally `char32_t` takes
 at least 32 bits, rather than exactly 32 bits).