Adding USB PD to my laptop
If you cautiously follow the Hackaday article you mentioned, then yes, the approximately 20V PD output will match-up okay with the specified 19V input required your computer. Give or take a volt (+/- 1V) here will likely not hurt anything here -- yet, it can be argued.
Notice carefully in the article, the hacker used an off-the-shelf USB PD &quot;trigger&quot; board to request 20V from the PD supply and that he skillfully wired it in.  In my findings, 20V comes out of PD supplies at something less... typically 19.9 or 19.8 or so.
Just a word of caution, be smart that your computer would be an expensive loss if you were unsuccessful. Maybe try this experiment on a breadboard circuit, first.