Promote andykellr to maintainer (#248)

Author: andykellr

README.md

@@ -42,13 +42,12 @@ specification markdown and as a prefix of the added proto field or message.
 ### Maintainers
 
 - [Tigran Najaryan](https://github.com/tigrannajaryan), Splunk
+- [Andy Keller](https://github.com/andykellr), Bindplane
 
 For more information about the maintainer role, see the [community repository](https://github.com/open-telemetry/community/blob/main/guides/contributor/membership.md#maintainer).
 
 ### Approvers
 
-- [Andy Keller](https://github.com/andykellr), Bindplane
-
 For more information about the approver role, see the [community repository](https://github.com/open-telemetry/community/blob/main/guides/contributor/membership.md#approver).
 
 ### Emeritus Approvers