add support xpath in playground button

[pouryet]

Using this code, we can see the xpath address for each element in the playground button. This can prevent possible bugs in finding the css element. Also, for this, we need to install the xpath plugin.
"cypress-xpath" plugin: "^2.0.1" added. To find xpath using playground, I remind you that after this change, you must find the elements with the get.xpath command.

According to my experiences using application testers, I found that finding elements using xpath is the best way to write tests. Also, if you don't use this feature like other testers, you will be left behind in the market. CSS is always changing and is not a good option for selecting elements. On the other hand, adding the xpath plugin alone is not enough to make testing easier because we have to manually find the xpaths and add them to the code. The best solution is to use the playground button.

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