Fix Vale issues for administration/instance_limits.md

What does this MR do and why?

This MR is going to resolve the issue #346851 (closed)

Screenshots or screen recordings

How to set up and validate locally

1. Install vale using brew install vale
2. In root directory, run vale doc/administration/instance_limits.md

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.