[CI] Minor script cleanups

The metrics script did not have a license header or a docstring. The
compute_projects_test.py file had a placeholder module level docstring
that I edited into something more reasonable.

Author: boomanaiden154

.ci/compute_projects_test.py

@@ -1,7 +1,7 @@
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-"""Does some stuff."""
+"""Tests for compute_projects.py"""
 
 import unittest
 

.ci/metrics/metrics.py

@@ -1,3 +1,13 @@
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+"""Collects Github metrics and uploads them to Grafana.
+
+This script contains machinery that will pull metrics periodically from Github
+about workflow runs. It will upload the collected metrics to the specified
+Grafana instance.
+"""
+
 import collections
 import datetime
 import github