feat: ✨ add image for Deutsch's Algorithm in IQC 006 documentation

Author: gracefullight

blog/2026/03/30/deutschs-algo.png

@@ -85,3 +85,5 @@ $$\ket{x}\ket{-}\mapsto (-1)^{f(x)} \ket{x} \ket{-}$$
 - Given a boolean function $f:\{0,1\}^{n} \to \{0,1\}$, determine if $f$ is constant or balanced.
 - **Constant**: same output for all inputs.
 - **Balanced**: outpus 0 for half the inputs and 1 for the other half.
+
+![Deutsch's Algorithm](./deutschs-algo.png)