docs: add a recipes section

docs/recipes/workarounds.md

@@ -0,0 +1,70 @@
+# Workarounds
+
+ - **[Switch to previous costume](#switch-to-previous-costume)**
+ - **[Switch to last costume](#switch-to-last-costume)**
+ - **[Sense if sprite is shown or hidden](#sense-if-sprite-is-shown-or-hidden)**
+ - **[Set pen color to a RGB (or RGBA) value](#set-pen-color-to-a-rgb-or-rgba-value)**
+ - **[Point towards X, Y](#point-towards-x-y)**
+ - **[Rotate around X, Y](#rotate-around-x-y)**
+
+## Switch to previous costume
+
+```goboscript
+%define previous_costume switch_costume "previous_costume"
+```
+
+## Switch to last costume
+
+```goboscript
+%define last_costume switch_costume 0
+```
+
+## Sense if sprite is shown or hidden
+
+```goboscript
+proc _show { visible = true; show; }
+proc _hide { visible = false; show; }
+%define show _show
+%define hide _hide
+```
+
+You can extend this recipe to implement sensing of other sprite properties, which
+Scratch does not provide a reporter block for. For example, you can implement
+sensing of the ghost effect of a sprite.
+
+## Set pen color to a RGB (or RGBA) value
+
+Use the `RGB()` and `RGBA()` macros provided in the standard library header `std/math`.
+
+```goboscript
+%include std/math
+set_pen_color RGB(red, green, blue);
+```
+
+## Point towards X, Y
+
+```goboscript
+proc point_towards_xy x, y {
+    point_in_direction atan($x - x_position() / $y - y_position());
+    if $y < y_position() {
+        turn_right 180;
+    }
+}
+```
+
+## Rotate around X, Y
+
+```goboscript
+%include std/math
+
+proc rotate_around x, y, degrees {
+    local dir = direction();
+    local dist = DIST($x, $y, x_position(), y_position());
+    point_towards_xy $x, $y;
+    goto
+        $x + dist * sin(direction() + 180 + $degrees),
+        $y + dist * cos(direction() + 180 + $degrees);
+    point_in_direction dir;
+    turn_right $degrees;
+}
+```

mkdocs.yml

@@ -27,6 +27,8 @@ nav:
           - Visual Studio Code: editor-integration/vscode.md
           - Sublime Text: editor-integration/sublime-text.md
           - Notepad++: editor-integration/notepad++.md
+    - Recipes:
+          - Workarounds: recipes/workarounds.md
 theme:
     name: material
     features: