Schema content-type fix (open-telemetry#3474)

Author: chalin

netlify.toml

@@ -13,4 +13,9 @@ force = true
 [[redirects]]
 from = "https://blog.opentelemetry.io/*"
 to = "https://opentelemetry.io/blog/:splat"
-force = true
+force = true
+
+[[headers]]
+  for = "/schemas/:version"
+  [headers.values]
+    content-type = "application/yaml"