Redirect /schemas/latest to latest schema (open-telemetry#3475)

Author: chalin

layouts/index.redirects

@@ -44,6 +44,11 @@
 /docs/reference/specification/*  /docs/specs/otel/:splat
 /docs/specification/otel/*       /docs/specs/otel/:splat
 
+{{ $schemaFiles := partial "schema-file-list" . -}}
+{{ $latestSchemaFile := index $schemaFiles 0 -}}
+
+/schemas/latest  /schemas/{{ $latestSchemaFile.Name }}
+
 {{/*
   Social-media image redirects. As mentioned in
   https://developers.facebook.com/docs/sharing/webmasters/images, we need to

layouts/partials/schema-file-list.html

@@ -0,0 +1,13 @@
+{{/*
+  Returns an array of schema files, sorted with the latest first.
+
+  Each schema file name is a semver. Sorting semver can be tricky, so for now we
+  just sort by file size, descending, which gives us the same as a semver sort.
+  This works because each published schema contains the text of all previously
+  published schemas, and hence must be larger in size.
+
+*/ -}}
+
+{{ $schemaFiles := readDir "content-modules/semantic-conventions/schemas" -}}
+{{ $schemaFilesSortedLatestFirst := sort $schemaFiles "Size" "desc" -}}
+{{ return $schemaFilesSortedLatestFirst -}}