doc: fix some links

Backport-PR-URL: #19447
PR-URL: #16202
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

Author: vsemozhetbyt

doc/api/n-api.md

@@ -3680,6 +3680,7 @@ NAPI_EXTERN napi_status napi_run_script(napi_env env,
 [Working with JavaScript Values]: #n_api_working_with_javascript_values
 [Working with JavaScript Values - Abstract Operations]: #n_api_working_with_javascript_values_abstract_operations
 
+[`napi_async_init`]: #n_api_napi_async_init
 [`napi_cancel_async_work`]: #n_api_napi_cancel_async_work
 [`napi_close_escapable_handle_scope`]: #n_api_napi_close_escapable_handle_scope
 [`napi_close_handle_scope`]: #n_api_napi_close_handle_scope