feat: add CODEOWNERS file while we're at it

.github/CODEOWNERS

@@ -0,0 +1,7 @@
+# Lines starting with '#' are comments.
+# Each line is a file pattern followed by one or more owners.
+# Documentation with syntax examples:
+# https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners
+
+# These owners will be the default owners for everything in the repo.
+*       @DataBiosphere/dsp-data-team-eng