TAPPX - Update tappx.md (#3144)

* TAPPX - Update tappx.md

We update with the changes of the prebid/prebid-server#1931 pull request.

* clarifying data type

* Hotfix

Change "gropu" mistake word to "group" correct word.

Co-authored-by: bretg <bgorsline@gmail.com>

dev-docs/bidders/tappx.md

@@ -27,6 +27,9 @@ Please contact tappx@tappx.com to get set up.
 | tappxkey | required | An ID which identifies the adunit | 'key1' | string |
 | endpoint | required | Endpoint provided to publisher | 'endpoint1' | string |
 | bidfloor | optional | Minimum bid for this impression expressed in CPM (USD) | 1.2 | number |
+| mktag | optional | An ID which identifies a group of adunits | 'key1' | string |
+| bcid | optional | Block list of CID | ["1234"] | array of strings |
+| bcrid | optional | Block list of CRID | ["1234"] | array of strings |
 
 ### Test Parameters