shared_ptr -> std::shared_ptr

This is one of the first commits in a plan to remove all `using namespace std;` lines in the entire codebase as it is considered anti-pattern today.

Minecraft.World/RiverInitLayer.cpp

@@ -1,7 +1,7 @@
 #include "stdafx.h"
 #include "net.minecraft.world.level.newbiome.layer.h"
 
-RiverInitLayer::RiverInitLayer(int64_t seed, shared_ptr<Layer>parent) : Layer(seed)
+RiverInitLayer::RiverInitLayer(int64_t seed, std::shared_ptr<Layer>parent) : Layer(seed)
 {
 	this->parent = parent;
 }