fix(head): update open-graph width and height protocol per ogp

[ssmendon]

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The https://ogp.me standard doesn't have an a property called "og:width" and "og:height".

The closest thing to that are "Structured Properties" for the image, which are actually "og:image:width" and "og:image:height".

This commit uses the correct property names.

For more information, read this excerpt from https://ogp.me/#structured:

Some properties can have extra metadata attached to them. These are specified in the same way as other metadata with property and content, but the property will have extra :.

The og:image property has some optional structured properties:

• og:image:url - Identical to og:image.
• og:image:secure_url - An alternate url to use if the webpage requires HTTPS.
• og:image:type - A MIME type for this image.
• og:image:width - The number of pixels wide.
• og:image:height - The number of pixels high.
• og:image:alt - A description of what is in the image (not a caption). If the page specifies an og:image it should specify og:image:alt.