pw_assert: Optionally disable CHECK value capture

Adds a config option to pw_assert to allow projects to disable CHECK
value captures for code size savings.

Change-Id: Icd1dc9e59849446e2c7e0fb72e9be2153efdd024
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/70161
Pigweed-Auto-Submit: Armando Montanez <amontanez@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>
diff --git a/pw_assert/docs.rst b/pw_assert/docs.rst
index d528a87..525050c 100644
--- a/pw_assert/docs.rst
+++ b/pw_assert/docs.rst
@@ -719,6 +719,14 @@
   This defaults to being disabled if ``NDEBUG`` is defined, else it is enabled
   by default.
 
+.. c:macro:: PW_ASSERT_CAPTURE_VALUES
+
+  Controls whether the evaluated values of a CHECK statement are captured as
+  arguments to the final string. Disabling this will reduce code size at CHECK
+  callsites, but slightly reduces debugability.
+
+  This defaults to enabled.
+
 -------------
 Compatibility
 -------------