Updated CODEOWNERS

Signed-off-by: Andre Wanlin <awanlin@spotify.com>

Author: awanlin

.github/CODEOWNERS

@@ -4,4 +4,4 @@
 # The last matching pattern takes precedence.
 # https://help.github.com/articles/about-codeowners/
 
-*         @backstage/techdocs-core
+*         @backstage/techdocs-maintainers @awanlin