Add support for relative paths when capturing image

[Sinled]

Some pages use relative paths for images, e.g. https://omnivore.app

when you add such link using auto-card-link, it saves image without base url, and it isn't shown in obsidian

e.g.

```cardlink
url: https://omnivore.app
title: "Omnivore"
description: "Omnivore is the free, open source, read-it-later app for serious readers."
host: omnivore.app
image: /static/images/og-homepage-03.png
```

It would be nice to change render so it uses base name when rendering image, or save full image url when creating card link.

Thanks.

[Sinled]

Is this project alive?

Would you accept pull request with this feature?

[Sinled]

It seems it is working now, thanks