readme: Addressed review comments #2

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
Co-authored-by: davidhorstmann-arm <70948878+davidhorstmann-arm@users.noreply.github.com>
diff --git a/README.md b/README.md
index f2e810e..7e44f21 100644
--- a/README.md
+++ b/README.md
@@ -255,7 +255,7 @@
 Mbed TLS is mostly written in portable C99; however, it has a few platform requirements that go beyond the standard, but are met by most modern architectures:
 
 - Bytes must be 8 bits.
-- `all-bits-zero` must be a valid representation of a null pointer.
+- All-bits-zero must be a valid representation of a null pointer.
 - Signed integers must be represented using two's complement.
 - `int` and `size_t` must be at least 32 bits wide.
 - The types `uint8_t`, `uint16_t`, `uint32_t` and their signed equivalents must be available.