Add targetevent to current versioned doc (facebook#4623)

Author: Abbondanzo

website/versioned_docs/version-0.79/targetevent.md

@@ -0,0 +1,29 @@
+---
+id: targetevent
+title: TargetEvent Object Type
+---
+
+`TargetEvent` object is returned in the callback as a result of focus change, for example `onFocus` or `onBlur` in the [TextInput](textinput) component.
+
+## Example
+
+```
+{
+    target: 1127
+}
+```
+
+## Keys and values
+
+### `target`
+
+The node id of the element receiving the TargetEvent.
+
+| Type                        | Optional |
+| --------------------------- | -------- |
+| number, `null`, `undefined` | No       |
+
+## Used by
+
+- [`TextInput`](textinput)
+- [`TouchableWithoutFeedback`](touchablewithoutfeedback)