let is a special word in javascript that tells the browser you're
				defining a new name for something. in this case the name is 'myElementInJS'
				then we are going to use a function that the browser gives us
				a function is basically a set question or procedure for the browser to perform
				in this case we'll use one that gives us a reference to a element on our page.
				the function is a part of the 'document' object which comes built into the browser,
				and is called 'querySelector'
				you call a function by putting parenthesis after its name like 'querySelector()'
				but you also need to tell the browser what selector you want to query! these
				are the same as css selectors you use for styling, though in this case you need
				to put them in quotations so that the browser knows they aren't javascript.
				in these snippets, any line that starts with '//' is ignored by the browser, its
				a way we can leave comments in our code to explain or remember what they are doing!