fix: reference group does not exist anymore use heading id

Author: ff6347

src/content/tutorials/en/setting-up-your-environment.mdx

@@ -239,7 +239,7 @@ Press and hold the mouse button as you drag the mouse pointer over the canvas.
 
 The code above draws white circles in the same position as the mouse pointer. When a mouse button is pressed, the circle’s color changes to black. 
 
-Visit the [p5.js reference](/reference/) for more p5.js functions like [2D Primitive shapes](/referencegroup-Shape). 
+Visit the [p5.js reference](/reference/) for more p5.js functions like [2D Primitive shapes](/reference/#Shape/). 
 
 
 ### Errors
@@ -358,7 +358,7 @@ function draw() {
 
 #### `background()`
 
-The `background()` function colors the background a specific color. You can use words inside quotations or numbers to color the background of the canvas. To learn more, visit the [p5.js reference](/reference/) pages for [`background()`](/reference/p5/background) & [color](/referencegroup-Color).
+The `background()` function colors the background a specific color. You can use words inside quotations or numbers to color the background of the canvas. To learn more, visit the [p5.js reference](/reference/) pages for [`background()`](/reference/p5/background) & [color](/reference/#Color).
 
 
 ### Step 6: Draw shapes on the canvas