add example to SDK usage page

Author: JoshuaMoelans

platform-includes/capture-message/native.mdx

@@ -20,6 +20,13 @@ To create and capture a manual event, follow these steps:
 2. Add custom attributes to the event, like a `message` or an `exception`.
 3. Send the event to Sentry by invoking `sentry_capture_event`.
 
+The custom attribute data must be of type `sentry_value_t`, which can store:
+* 32-bit signed integers,
+* 64-bit signed and unsigned integers,
+* double-precision floating-points,
+* null-terminated strings, as well as
+* lists and string-keyed maps containing `sentry_value_t` entries
+
 In a more complex example, it looks like this:
 
 ```c
@@ -29,9 +36,15 @@ sentry_value_set_by_key(event, "message", sentry_value_new_string("Hello!"));
 sentry_value_t screen = sentry_value_new_object();
 sentry_value_set_by_key(screen, "width", sentry_value_new_int32(1920));
 sentry_value_set_by_key(screen, "height", sentry_value_new_int32(1080));
+sentry_value_set_by_key(screen, "refresh_rate", sentry_value_new_double(29.97));
+
+sentry_value_t processed_files = sentry_value_new_list();
+sentry_value_append(processed_files, sentry_value_new_uint64(1073741824ULL));
+sentry_value_append(processed_files, sentry_value_new_uint64(2147483648ULL));
 
 sentry_value_t contexts = sentry_value_new_object();
 sentry_value_set_by_key(contexts, "screen_size", screen);
+sentry_value_set_by_key(contexts, "processed_files", processed_files);
 
 sentry_value_set_by_key(event, "contexts", contexts);
 sentry_capture_event(event);

platform-includes/performance/improving-data/native.mdx

@@ -7,12 +7,6 @@ The data must be of type `sentry_value_t`, which can store:
 * null-terminated strings, as well as
 * lists and string-keyed maps containing `sentry_value_t` entries
 
-<Alert level="warning">
-
-Currently, 64-bit unsigned integers are sent as strings, since they can't be processed as numerical values yet.
-
-</Alert>
-
 ### Adding Data Attributes to Transactions
 
 You can add data attributes to your transactions using the following API: