[jsx-no-target-blank] Option `enforceDynamicLinks` is described twice in docs

[gebsh]

In docs of the react/jsx-no-target-blank rule, the option enforceDynamicLinks is mentioned twice with almost exactly the same description.

I believe it may be a mistake introduced by subsequent changes to rule options, since descriptions of some options follow slightly different formatting.

[ljharb]

Thanks, a PR to fix that would be appreciated.

[gebsh]

Sure, I'll take a look at it and send a PR soon.