The popover script doesn’t ever start in until the DOM has finished
Loading, so wait for the script to be downloaded and parsed before
Showing the content to the user makes no sense.
The fetchData function suffer from a race condition. If the function is
called before the promise finishes, it will result in another pair of
HTTP request. This does not only make the function useless but
Actually, it makes it harmful as the data might be redownloaded twice.
Now fetchData is not a function but rather the promise by itself.
Previous callers are expected to await the variable instead, this
should be not concern as awaiting a promise multiple time in
JavaScript is completely safe.
Having the CSS and JS in the html template produces pages larger
than necessary, as each page need to contain all the js/css.
Separating them in appropriate files allow the browser to just download
them once and use them for all the pages. This is even more effective
with an aggressive cache policy for the js and css, something that can
be done without fear thanks to the implemented cache-busting.
Also, having then in separate files allows us to use Hugo pipelines
for minimizing the code.
