Make sentence bold

Author: sarnex

sycl/doc/extensions/experimental/sycl_ext_intel_grf_size.asciidoc

@@ -52,8 +52,8 @@ This extension also depends on the following other SYCL extensions:
 This is an experimental extension specification, intended to provide early access
 to features and gather community feedback. Interfaces defined in this specification
 are implemented in DPC++, but they are not finalized and may change incompatibly in
-future versions of DPC++ without prior notice. Shipping software products should not
-rely on APIs defined in this specification.
+future versions of DPC++ without prior notice. **Shipping software products should not
+rely on APIs defined in this specification.**
 
 == Backend support status