chore(docs): page.emulateVisionDeficiency docs (#6231)

This commit also removes our own custom type for defining the vision
deficiencies and uses the protocol's type. Now we generate docs for
those we get the docs generated for free for these. This is better than
us duplicating values for types in doc comments and having them become
outdated. If we use the protocol types directly then we ensure we're up
to date and in-sync.

Long term the docs will also link to the devtools-protocol viewer.

utils/doclint/check_public_api/index.js

@@ -653,7 +653,7 @@ function compareDocumentations(actual, expected) {
         'Method Page.emulateVisionDeficiency() type',
         {
           actualName: 'string',
-          expectedName: 'VisionDeficiency',
+          expectedName: 'Object',
         },
       ],
       [