Adding the Duck/Sidechain effect to Learn Docs (learn/effects.mdx)

Added the duck Effect to the section global effects.

Signed-off-by: fyynn <fyynn@noreply.codeberg.org>

website/src/pages/learn/effects.mdx

@@ -339,4 +339,18 @@ global effects use the same chain for all events of the same orbit:
 
 <JsDoc client:idle name="phasersweep" h={0} />
 
+## Duck
+
+### duckorbit
+
+<JsDoc client:idle name="duckorbit" h={0} />
+
+### duckattack
+
+<JsDoc client:idle name="duckattack" h={0} />
+
+### duckdepth
+
+<JsDoc client:idle name="duckdepth" h={0} />
+
 Next, we'll look at input / output via [MIDI, OSC and other methods](/learn/input-output).