Blog Graphic Template for FreeCAD

This issue is for an SVG template (Inkscape Editable) for FreeCAD blog posts.
The brief is as follows:

## Requirements for a blog post hero images template

### Ongoing work
The current website design is available here: https://marcuspollio.github.io/FreeCAD-website/.
Variations
Hero images

### Where they will show up:
1. The website homepage, a small thumbnail with a blog post title below.
2. The News section, a small thumbnail with a blog post title below.
Size / Side ratio: TBD

### Design considerations:
• The design should include elements of branding.
• Little or no text at all. We are going to have the title right next to the hero image, so duplicating the title doesn’t make sense
• Some hero images may have photo elements (showcases, events, interviews), others may have screenshot elements (weekly updates). Not all weekly updates have unique screenshots (maybe 20% of them so far).
• The right balance between variability and consistency. Not too monotonous when rendered in a grid with other thumbnails, but thumbnails on that grid shouldn't look all over the place either. This may involve some sort of color coding for categories, but it’s just one of the ideas.

## OpenGraph cards
Where they will show up: on social networks posts.
Size / Side ratio: TBD

### Design considerations:
• The design should include elements of branding.
• The design should take into consideration how unfurling works on various social platforms. Mainly, they display the tag contents, but not necessarily the <description> contents. So there should be no title duplication.

## Categories
We are currently targeting the following main categories:
• Development updates
• Tutorials
• Events
• Showcases
• FPA (FreeCAD Project Association) announcements
• Grants