docs: add suggestion for isVueInstance

Author: afontcu

docs/api/wrapper-array/isVueInstance.md

@@ -2,6 +2,10 @@
 
 ::: warning Deprecation warning
 `isVueInstance` is deprecated and will be removed in future releases.
+
+Most of the times, tests relying on `isVueInstance` provide little to no-value so you could simply remove them.
+
+If you want to keep these tests, a valid replacement is to assert that `wrapper.find(...).vm` exists.
 :::
 
 Assert every `Wrapper` in `WrapperArray` is Vue instance.

docs/api/wrapper/isVueInstance.md

@@ -2,6 +2,10 @@
 
 ::: warning Deprecation warning
 `isVueInstance` is deprecated and will be removed in future releases.
+
+Most of the times, tests relying on `isVueInstance` provide little to no-value so you could simply remove them.
+
+If you want to keep these tests, a valid replacement is to assert that `wrapper.find(...).vm` exists.
 :::
 
 Assert `Wrapper` is Vue instance.