Python scripts to do some simple changes in markdown files and filenames

• callout.py: change markdown > into <Callout> objects
• patters.py: various small regex patterns - the script might not work out of box, but the patterns can be useful for finding patterns via some IDE like vscode
• fix_images.py: fix paths in markdown image tags
• break.py: replace <br> with two spaces
• markdown_images: replace html image syntax with markdown image syntax
• markdown_links: replace html link syntax with markdown link syntax
• remove_id: removes id from article frontmatter

See the individual scripts for examples