feat(docs): Improved QInput example to prevent issue quasarframework#…

…11423 quasarframework#10376 quasarframework#10362 quasarframework#12431 (quasarframework#12432)

* fix(docs): Improved QInput example...

...to prevent issue duplicating

Related: [https://github.com/quasarframework/quasar/issues/11423](https://github.com/quasarframework/quasar/issues/11423), [https://github.com/quasarframework/quasar/issues/10376](https://github.com/quasarframework/quasar/issues/10376), [quasarframework#10362 [https://github.com/quasarframework/quasar/issues/12431](https://github.com/quasarframework/quasar/issues/12431).

* Update input.md

Co-authored-by: Razvan Stoenescu <razvan.stoenescu@gmail.com>

docs/src/pages/vue-components/input.md

@@ -74,6 +74,10 @@ Please check these resources for more information about native attributes (for i
 
 As a helper, you can use `clearable` prop so user can reset model to `null` through an appended icon. The second QInput in the example below is the equivalent of using `clearable`.
 
+::: warning
+Won't work with `v-model` managed input modifiers such as `.trim` because in that case Vue doesn't handle `null` values.
+:::
+
 <doc-example title="Clearable" file="QInput/Clearable" />
 
 ### Input types