Update plugin assets

[jeffpaul]

Within the .wordpress-org folder, add the following image assets to ensure proper, expected presentation for the plugin on its WP.org page:

• add banner image: banner-772x250.(jpg|png)
• add high-DPI banner image: banner-1544x500.(jpg|png)
• add icon: icon-128x128.(png|jpg)
• add high-DPI icon: icon-256x256.(png|jpg)
• add SVG icon: icon.svg
• add screenshots: screenshot-1.(png|jpg), screenshot-2.(png|jpg), ... screenshot-n.(png|jpg)

[jeffpaul]

Noting that we're blocked here until we receive the brand-styled banner and icon images.

[jeffpaul]

Once remaining plugin updates are done, we'll grab new screenshots to fully close out the work needed here.