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/Line.cs

@@ -0,0 +1,39 @@
+using System.Numerics;
+
+
+namespace Raylib_cs;
+
+public struct Line
+{
+    public Vector2 pointA;
+    public Vector2 pointB;
+
+    public Line(Vector2 p1, Vector2 p2)
+    {
+        pointA = p1;
+        pointB = p2;
+    }
+
+    public Line(Vector2 startPos, float endPosX, float endPosY)
+    {
+        pointA = startPos;
+        pointB = new Vector2(endPosX, endPosY);
+    }
+
+    public Line(float startPosX, float startPosY, Vector2 endPos)
+    {
+        pointA = new Vector2(startPosX, startPosY);
+        pointB = endPos;
+    }
+
+    public Line(float startPosX, float startPosY, float endPosX, float endPosY)
+    {
+        pointA = new Vector2(startPosX, startPosY);
+        pointB = new Vector2(endPosX, endPosY);
+    }
+
+    public readonly override string ToString()
+    {
+        return $"P1: {pointA}, P2: {pointB}";
+    }
+}