docs: improve FAQ wording per gregmarr's review suggestion

Clarify that JSON_BRACE_INIT_COPY_SEMANTICS replaces the
compiler-dependent behavior rather than just "not creating an array".

Author: ssam18

docs/mkdocs/docs/home/faq.md

@@ -46,7 +46,7 @@ for objects.
 
 **Opt-in copy semantics (since version 3.12.0)**
 
-If you define `JSON_BRACE_INIT_COPY_SEMANTICS` to `1` before including the library, single-element brace initialization is treated as copy/move instead of creating a single-element array:
+If you define `JSON_BRACE_INIT_COPY_SEMANTICS` to `1` before including the library, single-element brace initialization is treated as copy/move instead of being compiler-dependent whether it does that or creates a single-element array:
 
 ```cpp
 #define JSON_BRACE_INIT_COPY_SEMANTICS 1