Free CDN: jsDelivr+Github
CDN : Content Delivery Network
1.Find the release selection in Github respository
2.Find the release version or create a new release
3.Using jsDelivr fetch resource
https://cdn.jsdelivr.net/gh/[username]/[repository]@[version]/[file directory]
https://cdn.jsdelivr.net/gh/LiMarcus/portfolio@1.0/assets/css/timeline.css
4.we can omit release version or compress JS/CSS file
// load jQuery v3.2.1
https://cdn.jsdelivr.net/gh/jquery/jquery@3.2.1/dist/jquery.min.js
// load version range rather than specific version
https://cdn.jsdelivr.net/gh/jquery/jquery@3.2/dist/jquery.min.js https://cdn.jsdelivr.net/gh/jquery/jquery@3/dist/jquery.min.js
// omit version number to get newest version
https://cdn.jsdelivr.net/gh/jquery/jquery/dist/jquery.min.js
// add “.min” to any JS/CSS to get compressed file, if not exist, generate automatically.
https://cdn.jsdelivr.net/gh/jquery/jquery@3.2.1/src/core.min.js
// add '/' in the end to get directory list
https://cdn.jsdelivr.net/gh/jquery/jquery/