docs: refresh and improve the "named data" sphinx theme

Change-Id: I196c30f84ce4edd5cd10dfe3cab6ea2dc6947815
diff --git a/docs/conf.py b/docs/conf.py
index 696dcee..8ea25f5 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -85,6 +85,9 @@
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
 
+html_copy_source = False
+html_show_sourcelink = False
+
 # Disable syntax highlighting of code blocks by default.
 highlight_language = 'none'