chore: add codeowners file

hjr3 · hjr3 · commit b69a9b8e9f87 · 2024-03-06T06:08:09.000-05:00
This makes it clear who is maintaining which package. This will also
allow commit privileges for a specific package instead of the entire
repo.
diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
@@ -0,0 +1 @@
+/packages/pg-connection-string @hjr3
