Hello a few more remarks
The link is interesting if you want to create Google.kml. For Navi.kml with its special features rather less. E.G.

iGO.kml can do multilayer folders, description, address, phone number. But no line breaks and other formatting in the description.

MagicEarth.kml does not know folders and descriptions, nor line breaks. But it knows address, which can be used for the description, and it knows phone numbers. It could also call websites, but nobody knows how to import them.
By the way, if you name the same file "Favourites.kml", they will not be displayed as poi but as favourites.

MapsMe.kml does not know folders, only descriptions, but here line breaks work. You can also set the pin colours.

What I haven't figured out yet is how to import linked websites.