Remove //TODO placeholder (mdn#43267)

* fix(getelementattribute): replace //TODO placeholder with src

* Apply suggestion from @Josh-Cena

* Apply suggestion from @Josh-Cena

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Co-authored-by: Anurag <anurag@example.com>
Co-authored-by: Joshua Chen <sidachen2003@gmail.com>

Author: 3 people

files/en-us/web/webdriver/reference/classic/commands/getelementattribute/index.md

@@ -6,7 +6,7 @@ browser-compat: webdriver.classic.GetElementAttribute
 sidebar: webdriver
 ---
 
-The _Get Element Attribute_ [command](/en-US/docs/Web/WebDriver/Reference/Command) of the [WebDriver](/en-US/docs/Web/WebDriver) API returns the attribute of the referenced [web element](/en-US/docs/Web/WebDriver/Reference/WebElement). If for example the element is an {{HTMLElement("img")}}, the returned attribute is `"//TODO"`, which is equivalent to calling {{domxref("Element.getAttribute")}} on the element. For XML/XHTML documents it may be cased differently.
+The _Get Element Attribute_ [command](/en-US/docs/Web/WebDriver/Reference/Command) of the [WebDriver](/en-US/docs/Web/WebDriver) API returns the value associated with the attribute of the given name of the referenced [web element](/en-US/docs/Web/WebDriver/Reference/WebElement). For boolean attributes, the associated value is `"true"` if present. Absent attributes return `null`. It is equivalent to calling {{domxref("Element.getAttribute()")}} on the element in JavaScript.
 
 ## Syntax