[Extension Docs]Fix Download Links on Extension Home

File paths not working to download.
Updated location of image and linked to sample.

Bug: 806073
Change-Id: Id1e9b1794ad54dfe748ed8cc5da862fe6271a030
Reviewed-on: https://chromium-review.googlesource.com/935499Reviewed-by: Meggin Kearney <mkearney@chromium.org>
Commit-Queue: Crystal Lambert <crystallambert@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539053}

chrome/common/extensions/docs/templates/articles/extensions_index.html

@@ -55,14 +55,13 @@
 <h2 id="hello-extensions">Hello Extensions</h2>
 <p>
 Take a small step into extensions with this quick Hello Extensions example.
-Create a new directory to store files or download them
-<a href="examples/tutorials/hello_extensions" download="hello_extensions">
-  here.
-</a>
+Start by creating a new directory to store the extension's files,
+or download them from the
+<a href="/extensions/samples#search:hello">sample page</a>.
 </p>
 
 <p>
-Start by creating a file called <code>manifest.json</code>
+Next, add a file called <code>manifest.json</code>
 and include the following code:
 </p>
 <pre data-filename="manifest.json">
@@ -94,7 +93,7 @@ the extension has a popup file and icon declared under the
 </pre>
 <p>
   Download
-  <a href="examples/tutorials/hello_extensions/hello_extensions.png"
+  <a href="{{static}}/images/index/hello_extensions.png"
   download="hello_extensions.png">
   <code>hello_extensions.png</code> here</a>
    and then create a file titled <code>hello.html</code>: