feat(examples) add aniamtion examples

docs/overview/animation.md

@@ -47,7 +47,7 @@ lv_anim_set_values(&a, start, end);
 lv_anim_set_delay(&a, delay);
 
 /*Set path (curve). Default is linear*/
-lv_anim_set_path(&a, &path);
+lv_anim_set_path(&a, lv_anim_path_ease_in);
 
 /*Set a callback to call when animation is ready.*/
 lv_anim_set_ready_cb(&a, ready_cb);
@@ -76,48 +76,44 @@ lv_anim_start(&a);                             /*Start the animation*/
 ```
 
 
-You can apply **multiple different animations** on the same variable at the same time.
+You can apply multiple different animations on the same variable at the same time.
 For example, animate the x and y coordinates with `lv_obj_set_x` and `lv_obj_set_y`. However, only one animation can exist with a given variable and function pair.
 Therefore `lv_anim_start()` will delete the already existing variable-function animations.
 
 ## Animation path
 
-You can determinate the **path of animation**. In the most simple case, it is linear, which means the current value between *start* and *end*  is changed linearly.
-A *path* is mainly a function which calculates the next value to set based on the current state of the animation. Currently, there are the following built-in paths functions:
+You can determinate the path of animation. In the most simple case, it is linear, which means the current value between *start* and *end*  is changed linearly.
+A *path* is a function which calculates the next value to set based on the current state of the animation. Currently, there are the following built-in paths functions:
 
-- **lv_anim_path_linear** linear animation
-- **lv_anim_path_step** change in one step at the end
-- **lv_anim_path_ease_in** slow at the beginning
-- **lv_anim_path_ease_out** slow at the end
-- **lv_anim_path_ease_in_out** slow at the beginning and end too
-- **lv_anim_path_overshoot** overshoot the end value
-- **lv_anim_path_bounce** bounce back a little from the end value (like hitting a wall)
+- `lv_anim_path_linear` linear animation
+- `lv_anim_path_step` change in one step at the end
+- `lv_anim_path_ease_in` slow at the beginning
+- `lv_anim_path_ease_out` slow at the end
+- `lv_anim_path_ease_in_out` slow at the beginning and end too
+- `lv_anim_path_overshoot` overshoot the end value
+- `lv_anim_path_bounce` bounce back a little from the end value (like hitting a wall)
 
-A path can be initialized like this:
-```c
-lv_anim_path_t path;
-lv_anim_path_init(&path);
-lv_anim_path_set_cb(&path, lv_anim_path_overshoot);
-lv_anim_path_set_user_data(&path, &foo); /*Optional for custom functions*/
-
-/*Set the path in an animation*/
-lv_anim_set_path(&a, &path);
-```
 
 ## Speed vs time
-By default, you can set the animation time. But, in some cases, the **animation speed** is more practical.
+By default, you can set the animation time. But, in some cases, the animation speed is more practical.
 
 The `lv_anim_speed_to_time(speed, start, end)` function calculates the required time in milliseconds to reach the end value from a start value with the given speed.
 The speed is interpreted in _unit/sec_ dimension. For example,  `lv_anim_speed_to_time(20,0,100)` will give 5000 milliseconds. For example, in case of `lv_obj_set_x` *unit* is pixels so *20* means *20 px/sec* speed.
 
 ## Delete animations
 
-You can **delete an animation** by `lv_anim_del(var, func)` by providing the animated variable and its animator function.
+You can delete an animation by `lv_anim_del(var, func)` by providing the animated variable and its animator function.
 
+
+## Examples
+
+```eval_rst
+
+.. include:: ../../examples/anim/index.rst
+
+```
 ## API
 
-### Input device
-
 ```eval_rst
 
 .. doxygenfile:: lv_anim.h