start describing action properties for dataflow CRUD endpoints

docs/API-Reference/Product-APIs/Dataflows.md

@@ -0,0 +1,40 @@
+
+## Action Types
+### All action types
+#### Properties
+These properties are used by all action types.
+##### name
+The name of the action that will be displayed in the UI.
+##### id
+The id of the action. The id must be unique within the dataflow definition, but is not expected to be unique among the actions of other dataflow definitions.
+##### dependsOn
+The ids of all actions whose output will be consumed by the current action while producing its output rows.
+
+### Output DataSet
+#### Properties
+##### name
+The name of the action that will be displayed in the UI.
+##### id
+The id of the action. The id must be unique within the dataflow definition, but is not expected to be unique among the actions of other dataflow definitions.
+##### dependsOn
+In the case of an Output DataSet action, this list will contain the id of the single action that produces the rows that are published by this action.
+##### type
+Use the value 'PublishToVault' to specify an Output DataSet action.
+##### dataSource
+- name: the initial name of the output data source
+- description: a description of the output data source
+- guid: the internal id of the output data source
+##### versionChainType
+REPLACE | APPEND | UPSERT
+This describes the update method. More details can be found [here](https://domo-support.domo.com/s/article/000005541)
+To specify partitioned output, choose APPEND and specify the partition key column in the partitionIdColumns property
+##### upsertColumns
+No upsertColumns should be supplied unless versionChainType is UPSERT.
+##### partitionIdColumns
+An array of column names that constitute the partition key. No more than one partition id column is supported.
+No non-null value should be used for partitionIdColumns unless versionChainType = APPEND.
+##### retainPartitionExpression
+An expression that defines which partitions will be retained by domo and which will not be created (and which will be deleted if they exist).
+Any partition key that produces a true result from this expression will be maintained by domo. Other partitions will be deleted.
+This expression applies to all partitions that have been created in the past, as well as those that are included in the current execution.
+No non-null value should be used for retainPartitionExpression unless versionChainType = APPEND and partitionIdColumns contains a single column name.