fix doc

[mga-chka]

Description

cf a recent issue https://github.com/ContentSquare/chproxy/issues/391, the doc has a mistake. This PR fixes it. Please check the type of change your PR introduces:

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [x] Documentation content changes
• [ ] Other (please describe):

Checklist

• [ ] Linter passes correctly
• [ ] Add tests which fail without the change (if possible)
• [ ] All tests passing
• [ ] Extended the README / documentation, if necessary

Does this introduce a breaking change?

• [ ] Yes
• [ ] No

Further comments

[render[bot]]

Your Render PR Server URL is https://chproxy-pr-392.onrender.com.

Follow its progress at https://dashboard.render.com/static/srv-cmiifb6d3nmc73e66ff0.