docs: import csv corrections

packages/noco-docs/docs/135.extensions/030.upload-data-from-csv.md

@@ -11,16 +11,16 @@ The Import CSV Extension in NocoDB allows users to import data from CSV files di
 ## Importing Data
 ### Mode
 The Import CSV Extension supports two modes of data import:
-- **Add Records**: This option adds all records from the CSV file as new entries in the table.
-- **Merge Records**: This option updates existing records based on a specified field in the CSV file.
+- **Add Records**: This option adds all records from the CSV file as new entries in the specified table.
+- **Merge Records**: This option updates existing records based on a specified field (referred to as **merge field** in this context) in the CSV file.
   - *Create New Records Only*
-    - Only adds new records from the CSV. Existing records are not updated. New records are identified based on the merge field.
+    - Only adds new records from the CSV. Existing records are not updated. New records are identified based on the merge field specified.
   - *Update Existing Records Only* 
     - Only updates records that already exist in the table based on the merge field. New records are not added.
   - *Create and Update Records*
-    - Adds new records and updates existing ones as needed.
+    - Adds new records and updates existing ones as needed. New and existing records are identified based on the merge field.
 
-**Merge Field** is field that will be used to match records from the CSV file with existing records in NocoDB for the purpose of updating.
+**Merge Field** is field that will be used to match records from the CSV file with existing records in NocoDB table for the purpose of updating.
 
 **Field Mapping:** You can select the fields from the CSV file to import and map them to the corresponding fields in the NocoDB table.
 
@@ -32,7 +32,7 @@ To import data from a CSV file into NocoDB, drag-drop (or upload) the CSV file i
        - *Create New Records Only*, 
        - *Update Existing Records Only*, or 
        - *Create and Update Records*.
-     - Select "Merge Field"
+     - Select "Merge Field". Merge field typically will be your Primary Key or a unique identifier. Composite keys are not supported.
 3. **Use first record as header**: If the first row of the CSV file contains the column headers, enable this option to use them as the field names. 
 4. Map the CSV columns to the NocoDB fields.
 5. Click on the **Import** button to start the import process.