Update README.md (#1527)

* Update README.md

Fixed the 'unpacked extension' link and revised wording for clarity

* Update README.md

Revised wording [2]

* Clarify README

Better wording on the first two sentences

Author: gmf-uah

functional-samples/sample.optional_permissions/README.md

@@ -1,21 +1,21 @@
 ## Optional permissions in a new tab
 
-This new tab extension demonstrates how extensions can provide users the option to enable an additional feature. In this example, they optionally display top sites.
+This sample extension changes the **New Tab** page, prompting the user for permission to display their top sites. It demonstrates how extensions can provide users with the option to enable additional features.
 
-See [Optional permissions](https://developer.chrome.com/docs/extensions/reference/permissions/) to learn more.
+See [optional permissions](https://developer.chrome.com/docs/extensions/reference/permissions/) to learn more.
 
 ## Testing the extension
 
-Follow the instructions to load an [unpacked extension](https://developer.chrome.com/docs/extensions/mv3/getstarted/development-basics/#load-unpacked, then open a new tab.
+Follow the instructions to load an [unpacked extension](https://developer.chrome.com/docs/extensions/mv3/getstarted/development-basics/#load-unpacked), then open a new tab.
 
 It should look like this:
 
-<img src="../../.repo/images/optional-permissions-new-tab.png" alt="New tab with the focus of the day and optional feature button" width="500"/>
+<img src="../../.repo/images/optional-permissions-new-tab.png" alt="New tab with optional permission button" width="500"/>
 
-Then, click on "Allow Extension to Access to top sites". You will see the following message:
+Then, click on `Allow Extension to Access to Top Sites`. You will see the following message:
 
-<img src="../../.repo/images/optional-permissions-dialog.png" alt="Allow permissions dialog" width="400"/>
+<img src="../../.repo/images/optional-permissions-dialog.png" alt="Permissions dialog with Deny and Allow buttons respectively" width="400"/>
 
-If you accept, it will display a list of your top sites.
+Selecting `Allow` will display a list of the websites you visit most.
 
 <img src="../../.repo/images/optional-permissions-top-sites.png" alt="New tab displaying top sites" width="400"/>