doc(deprecated) Start documenting the diff between the old and the new API.

lib/deprecated/runtime-core/doc/new-api/instance.rs

@@ -0,0 +1,18 @@
+struct Instance {
+    module: Arc<ModuleInner>,
+    exports: Exports,
+}
+
+impl Instance {
+    fn load<T: Loader>(&self, loader: T) -> Result<T::Instnace, T::Error>;
+    fn fun<Args, Rets>(&self, name: &str) -> ResolveResult<Args, Rets, Wasm>;
+    fn resolve_func(&self, name: &str) -> ResolveError<usize>;
+    fn dyn_func(&self, name: &str) -> ResolveResult<DynFunc>;
+    fn call(&self, name: &str, params: &[Value]) -> CallResult<Vec<Value>>;
+    fn context(&self) -> &Ctx;
+    fn context_mut(&mut self) -> &mut Ctx;
+    fn exports(&self) -> ExportsIter;
+    fn module(&self) -> Module;
+    fn get_internal(&self, fields: &InternalField) -> u64;
+    fn set_internal(&self, fields: &InternalField, value: u64);
+}