Add CODEOWNERS so pull requests have reasonable defaults

.github/CODEOWNERS

@@ -0,0 +1,46 @@
+# 📀 Code Owners
+#
+# Copyright © 2023, California Institute of Technology ("Caltech").
+# U.S. Government sponsorship acknowledged.
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# • Redistributions of source code must retain the above copyright notice,
+#   this list of conditions and the following disclaimer.
+# • Redistributions must reproduce the above copyright notice, this list of
+#   conditions and the following disclaimer in the documentation and/or other
+#   materials provided with the distribution.
+# • Neither the name of Caltech nor its operating division, the Jet Propulsion
+#   Laboratory, nor the names of its contributors may be used to endorse or
+#   promote products derived from this software without specific prior written
+#   permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+#
+# Each line is a file pattern followed by one or more owners.
+#
+# These owners will be the default owners for everything in
+# the repo. Unless a later match takes precedence,
+# @global-owner1 and @global-owner2 will be requested for
+# review when someone opens a pull request.
+#
+# Go to https://github.com/orgs/NASA-PDS/teams to find out about our teams
+
+* @NASA-PDS/legacy-committers
+
+# For more information on populating this file, check out
+# https://docs.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners