I'm building NOS Workspace, a workspace for documents and HTML pages. With an HTML project proposal, you can paste the code or upload the .html file, then click the preview text to change a title, date or explanation.
Sign in to save the page and create a share link. The recipient can open it without an account. After you edit and save again, they can reopen the same link to read the updated page. You can try pasting, editing text and previewing before signing up.