add pip install to notebook

Author: CosmoMatt

notebooks/spherical_harmonic_transform.ipynb

@@ -28,6 +28,9 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "# Install s2fft\n",
+    "!pip install s2fft gwpy &> /dev/null\n",
+    "\n",
     "from jax.config import config\n",
     "config.update(\"jax_enable_x64\", True)\n",
     "\n",