fix: force redirects for domains (#76)

Author: vknabel

static/_redirects

@@ -6,8 +6,8 @@
 /:version/apidocs/apidocs https://docs.archive.metal-stack.io/:version/references/metal-api/index.html 302
 
 # non-migration related redirects
-https://docs.metal-stack.io https://metal-stack.io/docs/home
-https://docs.metal-stack.io/* https://metal-stack.io/:splat
+https://docs.metal-stack.io https://metal-stack.io/docs/home 301!
+https://docs.metal-stack.io/* https://metal-stack.io/:splat 301!
 /docs /docs/home
 
 # migrate archived paths to stable versions quickly