Adding license footer

jb/_config.yml

@@ -0,0 +1,28 @@
+# Book settings
+title: Elements of Data Science
+author: Allen B. Downey
+
+latex:
+  latex_documents:
+    targetname: book.tex
+
+execute:
+  execute_notebooks: 'off'
+
+repository:
+  url: https://github.com/AllenDowney/ElementsOfDataScience
+html:
+  use_repository_button: true
+
+  extra_footer: |
+    <div style="text-align: center;">
+      <a rel="license" href="https://creativecommons.org/licenses/by-nc-sa/4.0/">
+        <img alt="Creative Commons License" style="border-width:0"
+             src="https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png" />
+      </a>
+      <br />
+      This work is licensed under a
+      <a rel="license" href="https://creativecommons.org/licenses/by-nc-sa/4.0/">
+        Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
+      </a>.
+    </div>