I was thinking that it couldn't be done either, but if you look at something like the "Eat Munchies" game which is on the carossel at the top of the Web Store right now for me.
It has a description of:
Eets is a beautiful physics-based puzzle game by the award-winning team at Klei Entertainment.
*** Eets Munchies is in Early Beta! ***
The Eets have escaped, and players must lure them back by tempting them with cake! Using a host of amazing creatures, hand-animated by the award-winning team at Klei, players will cajole Eets home in puzzle after devious puzzle. Feed snacks to Eets to change its behavior, deform the terrain to meet your needs, or suck Eets into a whale and shoot it out its spout -- it's up to you!
Notice how the Bold part is not repeated in the rest of the description below.
When I type in my description, it takes the first 120 characters and makes them bold, then it repeats the entire thing again in a normal font.
Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo, *** This should be it's own line ***…
Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo,
*** This should be it's own line ***
tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Etiam porta sem malesuada magna mollis euismod. Donec sed odio dui.
There seems to be a super secret way to do the formatting. :-)