Define the syntax of browserVersion?

c.f. https://w3c.github.io/webdriver/#:~:text=%22browserVersion%22,-Compare%20value%20to, which says:

Compare value to the "browserVersion" entry in matched capabilities using an implementation-defined comparison algorithm. The comparison is to accept a value that places constraints on the version using the "<", "<=", ">", and ">=" operators.

And the note below:

Version comparison is left as an implementation detail since each user agent will likely have conflicting methods of encoding the user agent version, and standardizing these schemes is beyond the scope of this standard.

While I get we don't want to define the actual semantics of the comparison operators, we should define what the syntax of the browserVersion capability is itself.

Like, is browserVersion expected to take values like >=1.0.0? Can you combine multiple comparisons?

Start with the linked WebDriver specification section on the browserVersion capability and compare its stated comparison behavior with the questions in this issue. Done means the specification defines the capability's value syntax, including whether values such as >=1.0.0 and combined comparisons are allowed, without defining the comparison semantics.