Refactor micropub specific things out to a slice

slices/micropub/commands/posts/create_book_post.rb

@@ -0,0 +1,19 @@
+require "dry/monads"
+
+module Micropub
+  module Commands
+    module Posts
+      class CreateBookPost < Adamantium::Command
+        include Deps["repos.post_repo"]
+
+        include Dry::Monads[:result]
+
+        def call(post)
+          created_post = post_repo.create(post)
+
+          Success(created_post)
+        end
+      end
+    end
+  end
+end