[rshapes] Add DrawTriangleLinesEx()

Add DrawTriangleLinesEx() to the API for consistency with other shape drawing functions.

src/raylib.h

@@ -1284,6 +1284,7 @@ RLAPI void DrawLineDashed(Vector2 startPos, Vector2 endPos, int dashSize, int sp
 RLAPI void DrawTriangle(Vector2 v1, Vector2 v2, Vector2 v3, Color color);                                // Draw a color-filled triangle, counter-clockwise vertex order
 RLAPI void DrawTriangleGradient(Vector2 v1, Vector2 v2, Vector2 v3, Color c1, Color c2, Color c3);       // Draw triangle with interpolated colors, counter-clockwise vertex/color order
 RLAPI void DrawTriangleLines(Vector2 v1, Vector2 v2, Vector2 v3, Color color);                           // Draw triangle outline, counter-clockwise vertex order
+RLAPI void DrawTriangleLinesEx(Vector2 v1, Vector2 v2, Vector2 v3, float thick, Color color);            // Draw triangle outline with line thickness, counter-clockwise vertex order
 RLAPI void DrawTriangleFan(const Vector2 *points, int pointCount, Color color);                          // Draw a triangle fan defined by points (first vertex is the center)
 RLAPI void DrawTriangleStrip(const Vector2 *points, int pointCount, Color color);                        // Draw a triangle strip defined by points
 RLAPI void DrawRectangle(int posX, int posY, int width, int height, Color color);                        // Draw a color-filled rectangle