Add tech dev team as repo codeowners (#83)

.github/CODEOWNERS

@@ -0,0 +1,15 @@
+###############################################################################
+# GitHub Code-owner Configuration for Admin Backend
+#
+# Each line is a file pattern followed by one or more owners. See this link:
+# https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners#example-of-a-codeowners-file
+# for more information on configuring GitHub code owners, including examples.
+###############################################################################
+
+# These owners will be the default owners for everything in
+# the repo. Unless a later match takes precedence, members
+# of @climatepolicyradar/tech-devs will be requested for
+# review when someone opens a pull request. Teams should
+# be identified in the format @org/team-name. Teams must have
+# explicit write access to the repository.
+* @climatepolicyradar/tech-devs