Added UI and painted pendulum in different colors

src/assets/i18n/en.json

@@ -414,6 +414,16 @@
       "DISCLAIMER_4": "Light & Shadow: To visualize depth, light reflections and shadows (Ambient Occlusion) are simulated based on the curvature of the formula."
     }
   },
+  "PENDULUM": {
+    "TITLE": "Double pendulum",
+    "TRAIL_DECAY_TIME": "Trail length",
+    "DAMPING": "Damping",
+    "ATTRACTION": "Attraction",
+    "L1_LENGTH": "Length L1",
+    "L2_LENGTH": "Length L2",
+    "M1_MASS": "Mass M1",
+    "M2_MASS": "Mass M2"
+  },
   "ALGORITHM": {
     "TITLE": "Algorithms",
     "PATHFINDING": {