improve computed type signature

Author: yyx990803

src/api/computed-watch-api.md

@@ -34,10 +34,31 @@ console.log(count.value) // 0
 
 ```ts
 // read-only
-function computed<T>(getter: () => T): Readonly<Ref<Readonly<T>>>
+function computed<T>(
+  getter: () => T,
+  debuggerOptions?: DebuggerOptions
+): Readonly<Ref<Readonly<T>>>
 
 // writable
-function computed<T>(options: { get: () => T; set: (value: T) => void }): Ref<T>
+function computed<T>(
+  options: {
+    get: () => T
+    set: (value: T) => void
+  },
+  debuggerOptions?: DebuggerOptions
+): Ref<T>
+
+interface DebuggerOptions {
+  onTrack?: (event: DebuggerEvent) => void
+  onTrigger?: (event: DebuggerEvent) => void
+}
+
+interface DebuggerEvent {
+  effect: ReactiveEffect
+  target: any
+  type: OperationTypes
+  key: string | symbol | undefined
+}
 ```
 
 ## `watchEffect`
@@ -94,7 +115,7 @@ Alias of `watchEffect` with `flush: 'sync'` option.
 
 ## `watch`
 
-The `watch` API is the exact equivalent of the Options API [this.$watch](./instance-methods.html#watch) (and the corresponding [watch](./options-data.html#watch) option). `watch` requires watching a specific data source and applies side effects in a separate callback function. It also is lazy by default - i.e. the callback is only called when the watched source has changed.
+The `watch` API is the exact equivalent of the Options API [this.\$watch](./instance-methods.html#watch) (and the corresponding [watch](./options-data.html#watch) option). `watch` requires watching a specific data source and applies side effects in a separate callback function. It also is lazy by default - i.e. the callback is only called when the watched source has changed.
 
 - Compared to [watchEffect](#watcheffect), `watch` allows us to: