Update receiver/googlecloudpubsubreceiver/README.md

Co-authored-by: Anthony Mirabella <[email protected]>

receiver/googlecloudpubsubreceiver/README.md

@@ -23,8 +23,8 @@ receivers:
 ## Encoding
 
 You should not need to set the encoding of the subscription as the receiver will try to discover the type of the data
-by looking at the `ce-type` as `ce-datacontenttype` attributes of the message. Only when those attributes are not set 
-the `encoding` field in the configuration should be set. 
+by looking at the `ce-type` and `ce-datacontenttype` attributes of the message. Only when those attributes are not set 
+must the `encoding` field in the configuration be set. 
 
 | ce-type] | ce-datacontenttype | encoding | description |
 | --- | --- | --- | --- |