Fix ActiveTab sample extension (extension version in manifest needs to be a string).

BUG=None
TEST=The sample extension for activeTab should not fail to load unpacked.
Review URL: https://codereview.chromium.org/11777015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@175345 0039d316-1c4b-4281-b951-d872f2087c98

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

@@ -48,7 +48,7 @@ The main benefit of the <code>activeTab</code> permission is that it displays <e
 {
   "manifest_version": 2,
   "name": "Page Redder",
-  "version": 1,
+  "version": "1.0",
   <b>"permissions": ["activeTab"]</b>,
   "browser_action": {},
   "background": {