add new chemistry example

docs/source/examples/chemistry.md

@@ -0,0 +1,22 @@
+---
+jupytext:
+  text_representation:
+    extension: .md
+    format_name: myst
+    format_version: 0.13
+    jupytext_version: 1.14.1
+kernelspec:
+  display_name: qnum24
+  language: python
+  name: python3
+---
+
+# Chemistry example
+
+do chemistry with quantum
+
+```{code-cell} ipython3
+import mitiq
+
+# do some cool stuff here
+```