refactor!: replace pack! macros with derive-based pipeline types

Remove the `pack!`, `pack_err!`, `pack_structural!`, and
`pack_err_structural!` macros, replacing all pipeline type definitions
with `#[derive(Grouped)]` and `#[derive(Grouped, Wrap)]` attributes.
This changes the generated struct shape from named-field structs with an
`inner` field to tuple structs accessed via `.0`, and removes the
auto-generated `name` and `info` fields from error types.

1 files changed, 3 insertions, 2 deletions

diff --git a/docs/res/changlog_examples/feat_program_res.rs b/docs/res/changlog_examples/feat_program_res.rs
index 5133000..e9cc4e2 100644
--- a/docs/res/changlog_examples/feat_program_res.rs
+++ b/docs/res/changlog_examples/feat_program_res.rs
@@ -22,11 +22,12 @@ fn main() {
 
 dispatcher!("modify", EntryModify);
 
-pack!(DisplayGlobal = ());
+#[derive(Grouped, Wrap)]
+pub struct DisplayGlobal(());
 
 #[chain]
 fn modify(prev: EntryModify) {
-    let (name, age) = Picker::<()>::new(prev.inner)
+    let (name, age) = Picker::<()>::new(prev.0)
         .pick::<String>("--name")
         .pick::<i32>("--age")
         .unpack_directly();