Rename autogen library names

[na4zagin3]

Currently, autogen library names are prefixed with % and their packages are under satyrographos/experimental. We need to rename them to stabilize the feature.

It'd better to replace those prefixes with $.

(lang "0.0.3")

(doc
  (name "example-doc")
  (build
    ((satysfi "doc-example.saty" "-o" "doc-example-ja.pdf")
     (make "build-doc")))
  (dependencies (localized-today))
  (autogen ($today)))

@require: $today