Update 11-joint-inversion in notebooks

Author: santisoler

notebooks/joint-inversion/plot_inv_3_cross_gradient_pf.ipynb

@@ -135,9 +135,9 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "overwriting /home/ssoler/git/user-tutorials/notebooks/11-joint-inversion/cross_gradient_data.tar.gz\n",
+      "overwriting /home/ssoler/git/user-tutorials/notebooks/joint-inversion/cross_gradient_data.tar.gz\n",
       "Downloading https://storage.googleapis.com/simpeg/doc-assets/cross_gradient_data.tar.gz\n",
-      "   saved to: /home/ssoler/git/user-tutorials/notebooks/11-joint-inversion/cross_gradient_data.tar.gz\n",
+      "   saved to: /home/ssoler/git/user-tutorials/notebooks/joint-inversion/cross_gradient_data.tar.gz\n",
       "Download completed!\n"
      ]
     }