Add a README to link to the GDScript integration tests documentation
Add a README to link to the GDScript integration tests documentation

This makes the documentation about creating and running GDScript
integration tests more discoverable.

BastiaanOlij/godot,pkowal1982/godot,josempans/godot,godotengine/godot,guilhermefelipecgs/godot,BastiaanOlij/godot,godotengine/godot,josempans/godot,sanikoyes/godot,josempans/godot,vkbsb/godot,guilhermefelipecgs/godot,DmitriySalnikov/godot,pkowal1982/godot,Valentactive/godot,akien-mga/godot,josempans/godot,Faless/godot,akien-mga/godot,vkbsb/godot,Zylann/godot,BastiaanOlij/godot,Valentactive/godot,ZuBsPaCe/godot,Faless/godot,BastiaanOlij/godot,vnen/godot,sanikoyes/godot,vnen/godot,Shockblast/godot,vkbsb/godot,vkbsb/godot,firefly2442/godot,Faless/godot,Zylann/godot,guilhermefelipecgs/godot,godotengine/godot,ZuBsPaCe/godot,DmitriySalnikov/godot,vkbsb/godot,vkbsb/godot,Shockblast/godot,Valentactive/godot,Shockblast/godot,Zylann/godot,akien-mga/godot,josempans/godot,guilhermefelipecgs/godot,guilhermefelipecgs/godot,Shockblast/godot,Shockblast/godot,sanikoyes/godot,josempans/godot,Faless/godot,firefly2442/godot,Valentactive/godot,DmitriySalnikov/godot,guilhermefelipecgs/godot,ZuBsPaCe/godot,ZuBsPaCe/godot,BastiaanOlij/godot,ZuBsPaCe/godot,Zylann/godot,Faless/godot,pkowal1982/godot,akien-mga/godot,godotengine/godot,akien-mga/godot,vnen/godot,vnen/godot,Valentactive/godot,vkbsb/godot,godotengine/godot,Zylann/godot,sanikoyes/godot,akien-mga/godot,Shockblast/godot,Valentactive/godot,pkowal1982/godot,firefly2442/godot,DmitriySalnikov/godot,Valentactive/godot,pkowal1982/godot,godotengine/godot,Faless/godot,vkbsb/godot,vnen/godot,godotengine/godot,ZuBsPaCe/godot,josempans/godot,ZuBsPaCe/godot,firefly2442/godot,Shockblast/godot,pkowal1982/godot,guilhermefelipecgs/godot,vnen/godot,DmitriySalnikov/godot,pkowal1982/godot,godotengine/godot,vnen/godot,Valentactive/godot,BastiaanOlij/godot,Zylann/godot,sanikoyes/godot,Zylann/godot,DmitriySalnikov/godot,firefly2442/godot,ZuBsPaCe/godot,sanikoyes/godot,BastiaanOlij/godot,akien-mga/godot,Zylann/godot,firefly2442/godot,Faless/godot,BastiaanOlij/godot,sanikoyes/godot,akien-mga/godot,pkowal1982/godot,josempans/godot,Faless/godot,vnen/godot,guilhermefelipecgs/godot,firefly2442/godot,sanikoyes/godot,Shockblast/godot,firefly2442/godot,DmitriySalnikov/godot