Re-add cl-notebook now that it builds again.

quicklisp · quicklisp · commit 228704488e78 · 2020-12-12T13:34:24.000-05:00
diff --git a/projects/cl-notebook/source.txt b/projects/cl-notebook/source.txt
@@ -0,0 +1 @@
+git https://github.com/inaimathi/cl-notebook.git

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+git https://github.com/inaimathi/cl-notebook.git`