Updated CSS Selector help (markdown)

CSS-Selector-help.md

@@ -34,6 +34,15 @@ filter: `//h3/parent::a//@href`
 //img//@src
 ```
 
+# Select by `data-` source
+
+```
+<div data-test-id="productSizeList"...
+```
+
+`//div[@data-test-id = 'productSizeList']`
+
+
 # xPath and non-latin text getting garbled
 
 `xpath:` type filters and non-UTF8 is incompatable, If you see that your text is garbled `Нема планираних искључења.` becomes `Нема Ð¿Ð»Ð°Ð½Ð¸Ñ€Ð°Ð½Ð¸Ñ Ð¸ÑÐºÑ™ÑƒÑ‡ÐµÑšÐ°.` then you should convert your xPath filter to CSS https://extendsclass.com/xpath-to-css.html