Document that ViewportTexture is flipped on Y
Document that ViewportTexture is flipped on Y

Fixes #26141.

okamstudio/godot,vkbsb/godot,DmitriySalnikov/godot,Faless/godot,guilhermefelipecgs/godot,okamstudio/godot,Valentactive/godot,sanikoyes/godot,vnen/godot,vkbsb/godot,josempans/godot,guilhermefelipecgs/godot,Valentactive/godot,MarianoGnu/godot,vnen/godot,vnen/godot,ex/godot,Valentactive/godot,DmitriySalnikov/godot,vkbsb/godot,akien-mga/godot,Shockblast/godot,Zylann/godot,Paulloz/godot,groud/godot,Shockblast/godot,okamstudio/godot,MarianoGnu/godot,guilhermefelipecgs/godot,groud/godot,okamstudio/godot,vkbsb/godot,Zylann/godot,Faless/godot,godotengine/godot,godotengine/godot,DmitriySalnikov/godot,Shockblast/godot,godotengine/godot,vkbsb/godot,honix/godot,firefly2442/godot,BastiaanOlij/godot,DmitriySalnikov/godot,Paulloz/godot,pkowal1982/godot,guilhermefelipecgs/godot,ZuBsPaCe/godot,vnen/godot,firefly2442/godot,Paulloz/godot,sanikoyes/godot,vnen/godot,ZuBsPaCe/godot,BastiaanOlij/godot,josempans/godot,akien-mga/godot,groud/godot,pkowal1982/godot,sanikoyes/godot,pkowal1982/godot,BastiaanOlij/godot,Faless/godot,guilhermefelipecgs/godot,Zylann/godot,Valentactive/godot,DmitriySalnikov/godot,ZuBsPaCe/godot,pkowal1982/godot,ZuBsPaCe/godot,BastiaanOlij/godot,firefly2442/godot,groud/godot,sanikoyes/godot,BastiaanOlij/godot,groud/godot,ex/godot,ex/godot,akien-mga/godot,Faless/godot,Shockblast/godot,DmitriySalnikov/godot,Faless/godot,josempans/godot,Shockblast/godot,josempans/godot,guilhermefelipecgs/godot,guilhermefelipecgs/godot,firefly2442/godot,pkowal1982/godot,sanikoyes/godot,BastiaanOlij/godot,okamstudio/godot,ZuBsPaCe/godot,Shockblast/godot,BastiaanOlij/godot,ex/godot,josempans/godot,vnen/godot,Valentactive/godot,Zylann/godot,josempans/godot,vnen/godot,ex/godot,godotengine/godot,sanikoyes/godot,DmitriySalnikov/godot,Valentactive/godot,BastiaanOlij/godot,Zylann/godot,godotengine/godot,vkbsb/godot,Paulloz/godot,akien-mga/godot,okamstudio/godot,pkowal1982/godot,josempans/godot,josempans/godot,sanikoyes/godot,pkowal1982/godot,okamstudio/godot,godotengine/godot,guilhermefelipecgs/godot,ZuBsPaCe/godot,honix/godot,Paulloz/godot,MarianoGnu/godot,firefly2442/godot,firefly2442/godot,Zylann/godot,okamstudio/godot,okamstudio/godot,firefly2442/godot,honix/godot,honix/godot,akien-mga/godot,godotengine/godot,honix/godot,ZuBsPaCe/godot,akien-mga/godot,vnen/godot,MarianoGnu/godot,okamstudio/godot,Valentactive/godot,sanikoyes/godot,MarianoGnu/godot,Paulloz/godot,firefly2442/godot,vkbsb/godot,akien-mga/godot,Paulloz/godot,MarianoGnu/godot,Faless/godot,Faless/godot,ex/godot,godotengine/godot,pkowal1982/godot,Valentactive/godot,MarianoGnu/godot,ex/godot,ZuBsPaCe/godot,Zylann/godot,vkbsb/godot,MarianoGnu/godot,Zylann/godot,groud/godot,Faless/godot,Shockblast/godot,Shockblast/godot,honix/godot,akien-mga/godot,ex/godot