docs: improve TransitionGroupStub.md and TransitionStub.md (#200)

* Update TransitionGroupStub.md

* Update TransitionStub.md

* Update TransitionStub.md

* Update TransitionGroupStub.md

Author: 38elements

docs/en/api/components/TransitionGroupStub.md

@@ -1,16 +1,16 @@
 # TransitionGroupStub
 
-A component to stub the `transition-group` wrapper component. Instead of performing transitions asynchronously, it returns the child components synchronously.
+A component to stub the `transition-group` component. Instead of performing transitions asynchronously, it returns the child components synchronously.
 
-This is set to stub all `transition-group` components by default in the `vue-test-utils` config. To use the built-in `transition-group` wrapper component set `config.stubs['transition-group']` to false:
+This is set to stub all `transition-group` components by default in the `vue-test-utils` config. To use the built-in `transition-group`  component set `config.stubs['transition-group']` to false:
 
 ```js
 import VueTestUtils from 'vue-test-utils'
 
 VueTestUtils.config.stubs['transition-group'] = false
 ```
 
-To reset it to stub transition components:
+To reset it to stub `transition-group` components:
 
 ```js
 import VueTestUtils, { TransitionGroupStub } from 'vue-test-utils'

docs/en/api/components/TransitionStub.md

@@ -1,16 +1,16 @@
 # TransitionStub
 
-A component to stub the `transition` wrapper component. Instead of performing transitions asynchronously, it returns the child component synchronously.
+A component to stub the `transition` component. Instead of performing transitions asynchronously, it returns the child component synchronously.
 
-This is set to stub all `transition` components by default in the vue-test-utils config. To use the built-in `transition` wrapper component set `config.stubs.transition` to false:
+This is set to stub all `transition` components by default in the vue-test-utils config. To use the built-in `transition` component set `config.stubs.transition` to false:
 
 ```js
 import VueTestUtils from 'vue-test-utils'
 
 VueTestUtils.config.stubs.transition = false
 ```
 
-To reset it to stub transition components:
+To reset it to stub `transition` components:
 ```js
 import VueTestUtils, { TransitionStub } from 'vue-test-utils'