[Speed] Notes about the `Content-Length` header in responses#18539

pedrosousa merged 4 commits intoproductioncloudflare/cloudflare-docs:productionfrom

pedro/PCX-14477-speed-add-note-about-content-lengthcloudflare/cloudflare-docs:pedro/PCX-14477-speed-add-note-about-content-lengthCopy head branch name to clipboard