The same problem turns up in a few different shapes. If one of these is yours, this will save you time.
You built it, and now you maintain the words
You made a marketing site for your company or a client. It is finished. But the requests keep coming: change this heading, update that price, take down the old banner. Each one is two minutes of work and ten minutes of context-switching.
Give the person asking access to that one repository. They describe the change to ChatGPT or Claude; you read the commit later if you care to.
Several clients, several repositories
Freelancers and small studios end up holding every client’s site. Access here is per person and per repository, so each client reaches theirs and no one else’s.
You are not at your desk
A copy change should not require a laptop, a checkout and a build. With a chat window on your phone it does not.
The repository is private
Nothing has to be made public for someone to help you with it. Private repositories behave exactly like public ones here, on any GitHub plan.
One thing worth knowing: publishing a private repository as a GitHub Pages site needs GitHub Pro or Team. On the free plan, Azure Static Web Apps, Cloudflare Pages, Netlify and Vercel all build from private repositories at no cost — see support for the detail.