add some comments to the weaver config

Author: trentm

scripts/semconv/templates/registry/ts-experimental/weaver.yaml

@@ -1,10 +1,16 @@
+# ts-experimental/... generates the "semantic-conventions/src/experimental_*.ts"
+# files.
+
 # Notes:
 # - Use `""` and `null` with `exclude_stability` to skip attributes/metrics that
 #   accidentally do not have a stability set
 #   (e.g. https://github.com/open-telemetry/semantic-conventions/issues/1777).
 templates:
   - pattern: attributes.ts.j2
     file_name: "experimental_attributes.ts"
+    # This "exclude_stability" does *not* exclude "stable" because it needs
+    # to process *stable* enums that might have *unstable* members. (e.g.,
+    # `db.system.name` is stable, but some of its enum values are not.)
     filter: >
       semconv_attributes({
         "exclude_stability": ["", null]

scripts/semconv/templates/registry/ts-stable/weaver.yaml

@@ -1,3 +1,5 @@
+# ts-stable/... generates the "semantic-conventions/src/stable_*.ts" files.
+
 templates:
   - pattern: attributes.ts.j2
     file_name: "stable_attributes.ts"