weatherfeeder: split the former maximumdirect.net/weatherd project in two.

feedkit now contains a reusable core, while weatherfeeder is a concrete implementation that includes weather-specific functions.

internal/standards/doc.go

@@ -0,0 +1,8 @@
+// Package standards contains shared canonical vocabularies and lookup tables
+// used across multiple providers.
+//
+// The guiding principle is:
+// - Canonical types live in internal/model (provider-independent).
+// - Shared reference tables and helpers live here.
+// - Provider-specific mapping logic lives in internal/sources/<provider>.
+package standards