Add ImageKit and other options to image CDN recommendations

[imagekitio]

Description

Updated the image CDN recommendations section to include ImageKit alongside Cloudinary and Image Engine. Also added imgix to provide readers with a broader range of options.

Motivation

ImageKit is a widely used image CDN that provides real-time optimization, transformation, and delivery capabilities. Including it ensures readers have more comprehensive choices when selecting an image CDN. Adding imgix further enriches the list with another well-known alternative.

Additional details

• ImageKit website and docs.
• imgix website

[hamishwillee]

That's a fair positioning. Thank you.

[github-actions]

Preview URLs

• /en-US/docs/Learn_web_development/Extensions/Performance/Multimedia

External URLs (4)

URL: /en-US/docs/Learn_web_development/Extensions/Performance/Multimedia
Title: Multimedia: Images

• https://cloudinary.com/blog/make_all_images_on_your_website_responsive_in_3_easy_steps (1 time) (Note! This may be a new URL 👀)
• https://imageengine.io/ (1 time) (Note! This may be a new URL 👀)
• https://imagekit.io/docs/image-optimization (1 time) (Note! This may be a new URL 👀)
• https://www.imgix.com/ (1 time) (Note! This may be a new URL 👀)