Handling v-model modifiers playground has wrong example

[koeliga]

https://vuejs.org/guide/components/v-model.html#handling-v-model-modifiers

In the docs it says:

Let's create an example custom modifier, capitalize, that capitalizes the first letter of the string provided by the v-model binding:

and in the playground example it says:

This input capitalizes everything you enter:

When using the input it only capitalizes the first letter just like it says in the docs, so this is wrong.

[koeliga]

see #3134