Update ReadPixels description

Author: 4ian

extensions/reviewed/ReadPixels.json

@@ -1,7 +1,7 @@
 {
   "author": "@Bouh",
   "category": "Advanced",
-  "description": "\nThis extension allow to read pixels on screen.\n\n| Expression | Argument  | Type returned |\n|--|--|--|\n|  ReadPixelRed(x, y)  | position x: number, position y: number | number (0-255) |\n|  ReadPixelGreen(x, y)  | position x: number, position  y: number | number (0-255) |\n|  ReadPixelBlue(x, y)  | position x: number, position y: number | number (0-255) |\n|  ReadPixelAlpha(x, y)  | position x: number, position y: number | number (0-255) |",
+  "description": "Provides expressions allowing to read the RGB value of pixels on screen.",
   "extensionNamespace": "",
   "gdevelopVersion": ">=5.5.222",
   "fullName": "Read pixels",
@@ -246,4 +246,4 @@
     }
   ],
   "eventsBasedBehaviors": []
-}
+}