Add a scratchpad folder for your own notebooks which will be ignored

This is somewhere to put your own notebooks that you don't want to
pollute the git repo with, in order to reduce the stash/checkout/unstash
dances needed.

Signed-off-by: Chris Redpath <chris.redpath@arm.com>
diff --git a/ipynb/scratchpad/.gitignore b/ipynb/scratchpad/.gitignore
new file mode 100644
index 0000000..5e7d273
--- /dev/null
+++ b/ipynb/scratchpad/.gitignore
@@ -0,0 +1,4 @@
+# Ignore everything in this directory
+*
+# Except this file
+!.gitignore