I have looked at the current JS documentation, however I find it nearly unusable. Please note I am not asking for how to use JS, but how to use JS with Qualtrics.
If you look at your API documentation you provide very detailed information and sample code.
What I would like to see are the following:

• How do you read the value in a question, this should indicate how do you read the value from a dropdown, matrix etc


• How do you update the value in a question?


• How do you add a JS library?

Please provide some working samples that once can import into your own survey and use a base to learn and expand
I am asking for examples as one is given answers like the following in the community, and for me that is of no use:
Yes, it is possible to do calculations on values in text entry fields if the values are numeric. To dynamically display the result on the same page as the text entry question(s) you must use JavaScript.
w3schools.com has tutorials on html, css, JavaScript, and jQuery.
Regards