BridgeJS: Update PackageToJS template and add short instruction

Author: krodak

CONTRIBUTING.md

@@ -112,5 +112,9 @@ Run this script when you've made changes to:
 
 These changes require updating the pre-generated Swift bindings committed to the repository.
 
+**Adding new BridgeJS intrinsics:** 
+
+If you add new `@_extern(wasm, module: "bjs")` functions to [`BridgeJSInstrincics.swift`](Sources/JavaScriptKit/BridgeJSInstrincics.swift), also add corresponding stub entries to [`Plugins/PackageToJS/Templates/instantiate.js`](Plugins/PackageToJS/Templates/instantiate.js) in the `importObject["bjs"]` object. This allows packages without BridgeJS-generated code to instantiate successfully.
+
 ## Support
 If you have any questions or need assistance, feel free to reach out via [GitHub Issues](https://github.com/swiftwasm/JavaScriptKit/issues) or [Discord](https://discord.gg/ashJW8T8yp).

Plugins/PackageToJS/Templates/instantiate.js

@@ -54,6 +54,13 @@ async function createInstantiator(options, swift) {
                 swift_js_return_optional_float: unexpectedBjsCall,
                 swift_js_return_optional_heap_object: unexpectedBjsCall,
                 swift_js_return_optional_object: unexpectedBjsCall,
+                swift_js_get_optional_int_presence: unexpectedBjsCall,
+                swift_js_get_optional_int_value: unexpectedBjsCall,
+                swift_js_get_optional_string: unexpectedBjsCall,
+                swift_js_get_optional_float_presence: unexpectedBjsCall,
+                swift_js_get_optional_float_value: unexpectedBjsCall,
+                swift_js_get_optional_double_presence: unexpectedBjsCall,
+                swift_js_get_optional_double_value: unexpectedBjsCall,
             }
         },
         /** @param {WebAssembly.Instance} instance */