use page bundles and aliases for blog posts

to make it easier to maintain the blog and find blog posts, we could use page bundles (aka folders) that have the format yyyy-mm-dd_short-title/
inside the folder would then be an index.md with the content and also the images. see here https://gohugo.io/content-management/page-bundles/

we could then use aliases to keep the urls short and concise: https://gohugo.io/content-management/urls/