I'm trying to integrate my mod; (Featureful SDK)
Synopsis: Douglas Allen, born in 1971.He joined the U.S. Marine Corps, 1991. Mogadishu was the first big operation which he joined as Corporal. in 2004 Allen missing in the battlefield but he come back and will get his revenge who did this to him!
Judging by the screenshot you downloaded the wrong thing. What you downloaded is the whole github repository of said project. The majority of files aren't required and it makes only sense to have them if you intend on coding stuff into that SDK yourself.
Github.com <<< Here is the actual mod version download link for mappers to begin with right away.
Just extract it like any other mod into your Half-Life main directory and then move your maps, models over to that new folder featureful. Make also sure to add the featureful.FGD (containing the monsters for placement inside the editor) into your map editor later on.