README: use canonical image link

Author: williamboman

.npmignore

@@ -1,3 +1,4 @@
 src/
 npm-debug.log
 yarn-error.log
+example.gif

README.md

@@ -1,4 +1,4 @@
-<img align="center" alt="react-input-hints" src="example.gif" />
+<img align="center" alt="react-input-hints" src="https://raw.githubusercontent.com/williamboman/react-input-hints/gh-pages/example.gif" />
 
 *Animates input placeholders to make it look like they are being typed in realtime.*
 
@@ -23,6 +23,12 @@ ReactDOM.render(
 )
 ```
 
+## Installation
+
+```sh
+$ npm install react-input-hints
+```
+
 ## Props
 
 ### `placeholders` | `array`