Update README.md

Adds screenshot for “Rename Selected Files” workflow.
Adds “Create DMG Image”
Update retina quicklook
Update README.md
Adds a period.
Fixes Resize Image workflow with correct actions
Update readme
Update readme assets URL
Adds “Open with rmate” workflow
Adds “Compress SVG with SVGO” workflow
Update readme
Adds “Compress PNG with OptiPNG”
Remove shell echo comments
Adds “Compress JPEG with jpegoptim”
Reorder workflows in readme
Better document format
Better syntax
Convert “Compress SVG with SVGO” workflow from a folder action to a file action
Adds “Compress Images” workflow
Fixes syntax