updated readme with contribution invite

Author: bennettscience

README.md

@@ -5,6 +5,25 @@ Some of them are for admin purposes, others are for course management and
 pulling out some student data that is hard to get from the admin or course
 tools.
 
+## Using Scripts
+
+To use any of the Python scripts, use `pip install -r requirements.txt` to
+install `canvasapi` and dependencies. You should do this is a virtual
+environment, if possible. Type annotations are Python 3.7+, but scripts _should_
+work in 3.6+. The `canvasapi` library is 3.6+ only.
+
+## Contributions
+
+`pip install -r requirements-dev.txt` to install development packages. `mypy`,
+`black`, and `flake8` are for type checks and linting. I don't have many
+unittests because many of these scripts are one-offs and not too complex. For
+more complicated tools (like `assignment_rubrics`), I do have some tests in
+place to check the returned dictionary structure.
+
+This is open for contributions if you have scripts you'd like to share. Open a
+PR with the script file and an updated README with a short description of what
+it does.
+
 ### Scripts
 
 #### assignment_rubrics
@@ -15,25 +34,25 @@ scores for that assignment. Only Outcomes linked to rubrics are returned.
 **Return structure**
 
 ```javascript
-	{
-		[
-			'id': 1234,
-			'name': 'Last, First',
-			'rubric': {
-				'123_456': {
-					'comments': '',
-					'points': 3.0,
-					'rating_id': '7364_2363'
-				},
-				'987_654': {
-					'comments': '',
-					'points': 1.0,
-					'rating_id': '7364_4639'
-				},
-			'score': 92.0
-			}
-		...]
-	}
+{
+	[
+		'id': 1234,
+		'name': 'Last, First',
+		'rubric': {
+			'123_456': {
+				'comments': '',
+				'points': 3.0,
+				'rating_id': '7364_2363'
+			},
+			'987_654': {
+				'comments': '',
+				'points': 1.0,
+				'rating_id': '7364_4639'
+			},
+		'score': 92.0
+		}
+	...]
+}
 ```
 
 #### associate_blueprint