Tasks we perform with Sourcery are rather simple and can be replaced
with a basic collection of files and the generation of lists in the
new `swiftlint-dev` command. This spares contributors from installing
either Sourcery or Bazel.
Start with a command that generates a template for a new SwiftSyntax
rule. This tool could remain separate or be merged into the official
binary under a `dev` sub-command at a later point in time.