[doc] Update README.md with graal-related panels attributes

This code updates the READEME.md with the description of
two attributes used to load graal panels:
- code-license, upload license dashboard
- code-complexity, upload code complexity dashboard.

Signed-off-by: Valerio Cosentino <valcos@bitergia.com>

Author: valeriocos

README.md

@@ -47,6 +47,8 @@ SirMordred is the tool used to coordinate the execution of the GrimoireLab platf
  * **gitlab-issues** (bool: False): Enable GitLab issues menu
  * **gitlab-merges** (bool: False): Enable GitLab merge requests menu
  * **mattermost** (bool: False): Enable Mattermost menu
+ * **code-license** (bool: False): Enable code license menu. Note that if enabled, colic sections in the setup.cfg and projects.json should be declared
+ * **code-complexity** (bool: False): Enable code complexity menu. Note that if enabled, cocom sections in the setup.cfg and projects.json should be declared
  * **strict** (bool: True): Enable strict panels loading
 ### [phases]