Add documentation for writting mode on spark i/o

docs/content/_data/config/pipes/spark/batch.yaml

@@ -3,3 +3,8 @@ input:
 
 output:
   type: com.amadeus.dataio.pipes.spark.batch.StorageOutput
+  fields:
+    - name: mode
+      mandatory: "Yes"
+      description: Specifies the writing behavior when data or table already exists.
+      example: mode = "append"

docs/content/_data/config/pipes/spark/common.yaml

@@ -34,4 +34,4 @@ fields:
     description: Spark options, as key = value pairs. The list of available options is available in the official <a href="https://spark.apache.org/docs/3.5.0/api/java/org/apache/spark/sql/DataFrameReader.html" target="_blank">Spark API documentation</a> for the DataFrameReader
     example: options { header = true  }
 
-fields_warning: The date_filter field is never mandatory, but be aware that omitting it could result in processing years of data.
+fields_warning: The date_filter field is never mandatory, but be aware that omitting it could result in processing years of data.

docs/content/_data/config/pipes/spark/streaming.yaml

@@ -16,3 +16,7 @@ output:
       mandatory: "Yes"
       description: Controls the amount of time before returning from the streaming query, in hours.
       example: timeout = 24
+    - name: mode
+      mandatory: "Yes"
+      description: Specifies the writing behavior when data or table already exists.
+      example: mode = "append"