Increase spacing for images and callouts in blog detail pages

[inventarSarah]

In the blog detail pages, images and callouts in the main content should have a margin at the top and the bottom so that the content elements don't stick together so closely.

Example image:
The images already have a margin at the bottom but also should have the same margin at the top:

Example callouts:
Callouts are boxes with different background colors (some of them also have an icon in it). These do not have any margins currently and thus should have one at the bottom + top. I suggest using the same margin as for the images so the spacing is consistent

You can see images and callouts being used in this blog post: https://blog.globalping.io/run-a-globalping-probe-on-digitalocean-using-docker/

[jimaek]

Probably best to also reduce the padding on the sides to give more space to the text