[use-cases] Grammar 5.5.3 Example 5.3

[lauracarlson]

The Use Cases for WCAG 3.0 Conformance document has a couple of grammar issue in 5.5.3 Example 5.3:

"The company is considering to switch tools"
should likely be
"The company is considering switching tools"

and

"in an accessibility statements"
should be
"in an accessibility statement"