useWatch rules update: initial value

[SteffeyDev]

The useWatch docs currently state that "The initial return value from useWatch will always return what's inside of defaultValue or defaultValues from useForm."

I noticed in my own testing (codepen) that this doesn't seem to be the case, and useWatch seems to return the current form value on mount instead of the default values. This PR (which added this feature) and an inspection of the current code seem to confirm that the current form values are used on initial load if available, and only fall back on the default values if it has to (not sure what that case is when _state.mount is false).

Am I implementing useWatch in a non-standard or unusual way, or are the docs out of date here, or perhaps the way it is worded is confusing me?

[bluebill1049]

seems to return the current form value on mount instead of the default values.

you are right, would you like to improve the doc on that part?