[Fix_#873] Charles comments

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

Author: fjtirado

dsl-reference.md

@@ -1419,7 +1419,7 @@ 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. 
+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, the context is accessible within the expression scope: `.` if using jq. 
 
 Optionally, the context can have a predefined schema. 
 
@@ -1437,13 +1437,13 @@ 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
 ```