Change the wording and the `--debug` suggestion.
Add comma after "this is currently not supported", I was tempted to add
a semicolon before it to but I resisted.
Added a "then" after QtWebEngine version list, not a comma.
The most common questsions regarding greasemonkey support on IRC are
"how do I use it" and "why doesn't my script work", hopefully this can
be a starting point for most people experiencing issues.
