Fix _headers syntax (#546)

RaeesBhatti · web-flow · commit 5bd08e0d31bc · 2020-04-27T11:03:00.000+03:00
TOML content in a _headers file is not allowed and is ignore by production.
diff --git a/_headers b/_headers
@@ -1,4 +1,2 @@
-[[headers]]
-for = "/static/*"
-[headers.values]
-Cache-Control = "public, max-age=360000"
+/static/*
+  Cache-Control: "public, max-age=360000"
