Add to "## Basic functionality: Add tasks" (#112)

* Add to "## Basic functionality: Add tasks" 

As I was working through the tutorial I could not figure out why my list would not show up. I think it would be wise to make sure it is stated not to forget to set a height on the <ListView> component.

* Fixed a misspelling

I forgot the > add the end of my List View component.

Author: hines-sharrod

content/docs/en/getting-started/2-playground-tutorial.md

@@ -185,7 +185,7 @@ Use a `<ListView>` to show tasks below the input field.
 1. Configure the positioning of the elements within the grid.
     * Set the `<TextField>` to inhabit the first column and the first row.
     * Set the `<Button>` to inhabit the second column and the first row.
-1. Clean up sample code from the `<TextField>` and the `<ListView>`.
+1. Clean up sample code from the `<TextField>` and the `<ListView>` but make sure to set a height for the `<ListView>`.
 1. Log newly added tasks in the console.
 1. Add newly added tasks into the array of tasks. Use `unshift` to place new items at the top of the page.
 1. Clear the text field after input.
@@ -225,7 +225,7 @@ new Vue({
               <TextField row="0" col="0" v-model="textFieldValue" hint="Enter text..." editable="true" @returnPress="onButtonTap" /> <!-- Configures the text field and ensures that pressing Return on the keyboard produces the same result as tapping the button. -->
               <Button row="0" col="1" text="Add task" @tap="onButtonTap" />
             </GridLayout>
-            <ListView for="todo in todos" @itemTap="onItemTap">
+            <ListView for="todo in todos" @itemTap="onItemTap" height=""> <!-- Make sure to set a height or your list will not show -->
               <v-template>
                 <Label :text="todo.name" />
               </v-template>
@@ -337,4 +337,4 @@ new Vue({
   `,
 
 }).$start();
-```
+```