Extensions and explicit types

Added a new "RaylibExtensions" static class that gives overloaded extension methods to types so you can use them directly instead of calling the raylib class for everything.

Two new types: "Circle" and "Line"

All the "var" variables were changed to explicit types on the raylib class.

"MakeDirectory" overload, and string version of "GetApplicationDirectory" and "GetWorkingDirectory" methods.

Raylib-cs/types/Circle.cs

@@ -0,0 +1,69 @@
+using System.Numerics;
+
+namespace Raylib_cs;
+
+public struct Circle
+{
+    public Vector2 position;
+    public float radius;
+    public Color color;
+
+    public float X
+    {
+        get
+        {
+            return position.X;
+        }
+        set
+        {
+            position.Y = value;
+        }
+    }
+
+    public float Y
+    {
+        get
+        {
+            return position.Y;
+        }
+        set
+        {
+            position.Y = value;
+        }
+    }
+
+    public Circle(Vector2 position)
+    {
+        this.position = position;
+    }
+
+    public Circle(float x, float y)
+    {
+        position = new Vector2(x, y);
+    }
+
+    public Circle(float x, float y, Color color)
+    {
+        position = new Vector2(x, y);
+        this.color = color;
+    }
+
+    public Circle(Vector2 position, float radius)
+    {
+        this.position = position;
+        this.radius = radius;
+    }
+
+    public Circle(float x, float y, float radius)
+    {
+        position = new Vector2(x, y);
+        this.radius = radius;
+    }
+
+    public Circle(Vector2 position, float radius, Color color)
+    {
+        this.position = position;
+        this.radius = radius;
+        this.color = color;
+    }
+}