This example shows how to create beautiful multi-axis charts
Description
This example shows how to build a multi-axis chart by using `axes` property and specifying the `axis` for each column.
For example:
```
...
"columns"=>array(
"category",
"sale"=>array(
...
"axis" => "A",
),
"profit"=>array(
...
"axis" => "B",
),
),
"axes" => [
"A" => [
"type" => "linear",
...
],
"B" => [
"type" => "linear",
...
],
],
...
```