chore: added record array and optional data type odcumentation

Author: david-roper

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

@@ -41,12 +41,30 @@ Open Data Capture allows you to visualize numeric measures over time in a single
 
     Some forms may have Zod field types that are challenging to represent in a standard CSV format. Therefore, specific notations must be used to ensure the upload feature can properly parse the data.
 
-    For example: If a form has a field that accepts a set of data, such as a multi-option checklist with options a, b, and c, the proper notation for the data would be:
+    - **_Set Data_**
 
-    - SET(a,b)
-    - SET(a,b,c)
-    - SET(a)
+      If a form has a field that accepts a set of data, such as a multi-option checklist with options a, b, and c, the proper notation for the data would be:
 
-    This format allows the upload feature to correctly interpret the selected options.
+      - SET(a,b)
+      - SET(a,b,c)
+      - SET(a)
+
+      This format allows the upload feature to correctly interpret the selected options.
+
+    - **_Record Array Data_**
+
+      Record array data is a custom form a data entry for when there can be multiple records for one question. For example, the types of scans and their info in a MRI form. If a record contains a set of questions/ data fields A, B, and C, the proper notation for data entry would be as follows:
+
+      - RECORD_ARRAY(A: dataEntryForA, B: dataEntryForB, C: dataEntryForC ;)
+
+      If the record array question contains multiple records the data entry would look like so:
+
+      - RECORD_ARRAY(A: dataEntryForA, B: dataEntryForB, C: dataEntryForC ; A: dataEntryForA2, B: dataEntryForB2, C: dataEntryForC2 )
+
+      Note that every ',' notates an new entry in the record, whilst every ';' notates and new record in the record array
+
+    - **_Optional Data_**
+
+      Whenever data is optional within a form it can be left empty in a form as still be properly submitted. Any optional data column in the csv template will have an "(optional)" tag attached to its sample data entry, which allows for any entry in the column to be left blank. This is usually done in that case of when one column value depends on another. For example, a sessionFailed column would be followed by a an optional reasonForFailure column.
 
 </Steps>