chore: add sample csv template table

Author: david-roper

docs/en/3-guides/3.3-how-to-upload-data.md

@@ -70,3 +70,9 @@ Open Data Capture allows you to visualize numeric measures over time in a single
 </Steps>
 
 ### Sample CSV Data
+
+This section will present how to properly fill in a template csv from the upload feature. Say we download the following csv template that looks like this below.
+
+| subjectID | date       | stringQuestion | setQuestion     | optionalQuestion | recordArrayQuestion                                  |
+| :-------- | :--------- | :------------- | :-------------- | :--------------- | :--------------------------------------------------- |
+| string    | yyyy-mm-dd | yes/no         | SET(A/B/C, ...) | A/B (optional)   | RECORD_ARRAY(testString: A/B/C, testNumber: number;) |