docs: Document Snowflake DML write support

Add write support section to Snowflake data connector docs documenting
INSERT INTO, UPDATE, and DELETE operations with access: read_write.

Author: claudespice

website/docs/components/data-connectors/snowflake.md

@@ -215,6 +215,36 @@ The connector supports password-based and [key-pair](https://docs.snowflake.com/
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+## Write Support
+
+This connector supports writing data to Snowflake tables using SQL [`INSERT INTO`](../../reference/sql/dml#insert), [`UPDATE`](../../reference/sql/dml#update), and [`DELETE FROM`](../../reference/sql/dml#delete) statements.
+
+To enable writes, set `access: read_write` on the dataset:
+
+```yaml
+datasets:
+  - from: snowflake:DATABASE.SCHEMA.TABLE
+    name: table
+    access: read_write
+    params:
+      snowflake_warehouse: COMPUTE_WH
+      snowflake_role: accountadmin
+```
+
+```sql
+-- Insert rows
+INSERT INTO table (id, name, amount)
+VALUES (1, 'Alice', 100.0), (2, 'Bob', 200.0);
+
+-- Update rows
+UPDATE table SET amount = 150.0 WHERE id = 1;
+
+-- Delete rows
+DELETE FROM table WHERE id = 2;
+```
+
+For more details, see [Data Ingestion](../../features/data-ingestion).
+
 ## Example
 
 ```yaml