Fix Issue about addons.md's Wrong links (reactjs#1023)

* Edit addons.md's link to right link

* Update addons.md

Author: Brew-Brew

content/docs/addons.md

@@ -10,26 +10,26 @@ permalink: docs/addons.html
 
 The React add-ons are a collection of useful utility modules for building React apps. **These should be considered experimental** and tend to change more often than the core.
 
-- [`createFragment`](create-fragment.html), to create a set of externally-keyed children.
+- [`createFragment`](/docs/create-fragment.html), to create a set of externally-keyed children.
 
 The add-ons below are in the development (unminified) version of React only:
 
-- [`Perf`](perf.html), a performance profiling tool for finding optimization opportunities.
-- [`ReactTestUtils`](test-utils.html), simple helpers for writing test cases.
+- [`Perf`](/docs/perf.html), a performance profiling tool for finding optimization opportunities.
+- [`ReactTestUtils`](/docs/test-utils.html), simple helpers for writing test cases.
 
 ### Legacy Add-ons
 
 The add-ons below are considered legacy and their use is discouraged. They will keep working in observable future, but there is no further development.
 
-- [`PureRenderMixin`](pure-render-mixin.html). Use [`React.PureComponent`](/docs/react-api.html#reactpurecomponent) instead.
-- [`shallowCompare`](shallow-compare.html), a helper function that performs a shallow comparison for props and state in a component to decide if a component should update. We recommend using [`React.PureComponent`](/docs/react-api.html#reactpurecomponent) instead.
-- [`update`](update.html). Use [`kolodny/immutability-helper`](https://github.com/kolodny/immutability-helper) instead.
-- [`ReactDOMFactories`](dom-factories.html), pre-configured DOM factories to make React easier to use without JSX.
+- [`PureRenderMixin`](/docs/pure-render-mixin.html). Use [`React.PureComponent`](/docs/react-api.html#reactpurecomponent) instead.
+- [`shallowCompare`](/docs/shallow-compare.html), a helper function that performs a shallow comparison for props and state in a component to decide if a component should update. We recommend using [`React.PureComponent`](/docs/react-api.html#reactpurecomponent) instead.
+- [`update`](/docs/update.html). Use [`kolodny/immutability-helper`](https://github.com/kolodny/immutability-helper) instead.
+- [`ReactDOMFactories`](https://www.npmjs.com/package/react-dom-factories), pre-configured DOM factories to make React easier to use without JSX.
 
 ### Deprecated Add-ons
 
-- [`LinkedStateMixin`](two-way-binding-helpers.html) has been deprecated.
-- [`TransitionGroup` and `CSSTransitionGroup`](animation.html) have been deprecated in favor of [their drop-in replacements](https://github.com/reactjs/react-transition-group/tree/v1-stable).
+- [`LinkedStateMixin`](/docs/two-way-binding-helpers.html) has been deprecated.
+- [`TransitionGroup` and `CSSTransitionGroup`](/docs/animation.html) have been deprecated in favor of [their drop-in replacements](https://github.com/reactjs/react-transition-group/tree/v1-stable).
 
 ## Using React with Add-ons
 
@@ -40,7 +40,7 @@ import createFragment from 'react-addons-create-fragment'; // ES6
 var createFragment = require('react-addons-create-fragment'); // ES5 with npm
 ```
 
-When using a CDN, you can use `react-with-addons.js` instead of `react.js`:
+When using React 15 or earlier from a CDN, you can use `react-with-addons.js` instead of `react.js`:
 
 ```html
 <script src="https://unpkg.com/react@15/dist/react-with-addons.js"></script>