Suggestion: Allow function names starting with @

Considering the @reactive decorator, its usage is very clear: `@reactive accessor value`. However for the definition it is not that clear: ```js function reactive(target, desc) { // ... return { get, set, init } } ``` It may looks more confusing if the decorator itself takes arguments. So if it can be defined with a @ prefix in its name then everyone knows it is a decorator: ```js function @reactive(target, desc) { } ``` And this also allows decorators and normal functions share names: ```js function @foo () {} funcition foo() {} foo() // function foo is called @foo // function @foo is chosen because it is more specific. bar ```