index: change welcome image to fedoracoreos-logo.svg

[watsondeeuh]

The official logo, fedoracoreos-logo.svg, is visually to be displayed as the welcome image to the docs.

The old image, welcomefedoracoreos.jpg, looks like a gravestone.

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Every single time that I visit the index of Fedora CoreOS Documentation I see a gravestone:

Please, consider changing this welcome ~gravestone~ image with the official logo. Thanks

[dustymabe]

what's the image you propose replacing it with?

[watsondeeuh]

@dustymabe, as you can see in my commit, I'm proposing the use of the official logo that is already in this repository: fedoracoreos-logo.svg

[dustymabe]

Let's do it!