Added instructions on extracting other data

Parser/extraction-lib.py

@@ -372,3 +372,29 @@ if __name__ == "__main__":
             version1.load_to_db(db_connection)
             version2.load_to_db(db_connection)
             #print(db_connection)
+
+"""
+Documentation:
+
+TO add a new field to extraction-lib
+
+1. Locate the field in the HTML
+    - form id (e.g. <form id="form_StudyStatus> gives the form id "form_StudyStatus)
+    - Table row's data label. This corresponds to the text of first column in the row and will 
+    look something like 
+        <td class="rowLabel" style="min-width: 210px;">Record Verification:</td>.
+    "Record Verification:" is the data label in the example above.
+2. Identify what data you will be extracting 
+    - type (date, text, int, etc)
+    - if it contains a category ([Actual] vs [Anticipated] etc)
+3. Add data to:
+    - sql table: history.trial_snapshots
+    - the VersionData class
+    - the VersionData.load_to_db() function
+4. Ensure the field matcher in `get_forms(*)` is matching on the form ID and has a function processing the form
+5. Ensure the function processing the form has a match entry to proceess the row
+    - This should match on data label and then process the data by
+        - splitting into old and new versions
+        - Extracting the data for both old and new
+        - add the data to the passed VersionData objects
+"""