docs: add short explanations to motion directives

docs/content/2.features/1.directive-usage.md

@@ -16,13 +16,13 @@ Once put on an element, the v-motion will allow you to write your variants as pr
 
 The supported variants props are the following:
 
-- **`initial`**
-- **`enter`**
-- **`visible`**
-- **`visible-once`**
-- **`hovered`**
-- **`focused`**
-- **`tapped`**
+- **`initial`**: The properties the element will equip before it is mounted.
+- **`enter`**: The properties the element will equip after it is mounted.
+- **`visible`**: The properties the element will equip every time it is within view. Once it is out of view, the `initial` properties will be applied.
+- **`visible-once`**: The properties the element will equip once it is within view.
+- **`hovered`**: The properties the element will equip when the pointer enters its area.
+- **`focused`**: The properties the element will equip when the element receives focus.
+- **`tapped`**: The properties the element will equip upon clicking (mouse) or tapping (touch devices).
 
 You can also pass your variants as an object using the `:variants` prop.