Function: isMarkup(string)

Description: Checks if a string consists of HTML or XML markup.

Returns: True if yes, False otherwise.

Note: The isMarkup() function does not support chaining.

Example:

// Check if a string consists of HTML or XML markup

var isMarkup = $A.isMarkup('This is a test.'); // Returns false

var isMarkup = $A.isMarkup('<b>This is a test.</b>'); // Returns true