[Fix_#873] Charles comments

Signed-off-by: Francisco Javier Tirado Sarti <ftirados@redhat.com>

Author: fjtirado

dsl-reference.md

@@ -1419,34 +1419,31 @@ to: '.petList += [ . ]'
 
 ### Export
 
-Certain task needs to set the context of the workflow using the task output for later usage. User set the content of the context through a runtime expression. The result of the expression is the new value of the context. If user want to merge the new data into the current context, he might do that using `$context` variable. 
-
-Optionally, the context can have a predefined schema. 
+Certain task needs to set the context of the workflow using the task output for later usage. User set the content of the context through a runtime expression. The result of the expression is the new value of the context. For convenience, the previous context value is accessible within the expression scope. For example, `.` if using jq. 
 
+Optionally, the context might have an associated schema. 
 
 #### Properties
 
 | Property | Type | Required | Description |
 |----------|:----:|:--------:|-------------|
 | schema | [`schema`](#schema) | `no` | The [`schema`](#schema) used to describe and validate context.<br>*Included to handle the non frequent case in which the context has a known format.* |
-| as | `string`<br>`object` | `no` | A [runtime expression](#runtime-expressions), if any, used to set the context value. |
+| as | `string`<br>`object` | `no` | A runtime expression, if any, used to export the output data to the context. |
 
 #### Examples
 
-Assuming the output of the task is a json object (not primitive, not array)
 Merge into the current context the output of the task. 
 
 ```yaml
-as: '$context+=.'
+as: '.+$output'
 ```
 
 Replace the context with the output of the task. 
 
 ```yaml
-as: .
+as: $output
 ```
 
-
 ### Schema
 
 Describes a data schema.