release.nix -> default.nix

the default should be to build all the images

dockerhub-metadata

@@ -15,7 +15,7 @@ nix_eval() {
   nix-instantiate --strict --eval --json "$@"
 }
 
-releases_json=$(nix_eval release.nix)
+releases_json=$(nix_eval)
 
 to_json() {
   local desc=$1 full_desc=$2
@@ -29,7 +29,7 @@ echo "=== Updating Docker Hub project descriptions"
 
 for attr in $(echo "$releases_json" | jq -r "keys[]") ; do
   echo "--- $attr"
-  desc=$(nix_eval ./release.nix -A "$attr.meta.description" | jq -r .)
+  desc=$(nix_eval -A "$attr.meta.description" | jq -r .)
 
   if [[ -f "$attr/README.md" ]]; then
     full_desc=$(< "$attr/README.md")