ignore submission files from repo

Author: afeld

.gitignore

@@ -16,4 +16,5 @@ Untitled.ipynb
 !.vscode/settings.json
 
 extras/autograder/results/
+extras/autograder/submission/
 autograder.zip

Makefile

@@ -33,7 +33,7 @@ update_packages:
 
 # based on https://gradescope-autograders.readthedocs.io/en/latest/manual_docker/
 autograde:
-	mkdir -p ./extras/autograder/results
+	mkdir -p ./extras/autograder/results ./extras/autograder/results
 
 	docker run --rm \
 		-v ./extras/autograder:/autograder \

extras/autograder/submission/example.ipynb

@@ -127,7 +127,7 @@ Most of the issues are around Plotly rendering. Things that have been hit repeat
 
 ## Autograder
 
-Requires [Docker](https://www.docker.com/).
+Requires [Docker](https://www.docker.com/). Put files in `extras/autograder/submission/`, then run:
 
 ```sh
 make autograde