chore: add missing docs lint and document public API

Add `#![deny(missing_docs)]` across multiple crates and fill in
documentation for all public items, including struct fields, enum
variants, trait methods, and proc macros.  Also mark two shell scripts
as executable.

3 files changed, 18 insertions, 0 deletions

diff --git a/arg_picker/src/lib.rs b/arg_picker/src/lib.rs
index 285cd16..d292826 100644
--- a/arg_picker/src/lib.rs
+++ b/arg_picker/src/lib.rs
@@ -1,4 +1,5 @@
 #![doc = include_str!("../README.md")]
+#![deny(missing_docs)]
 
 mod builtin;
 
diff --git a/arg_picker/src/pickable/multi_pickable.rs b/arg_picker/src/pickable/multi_pickable.rs
index 84a8068..404c23b 100644
--- a/arg_picker/src/pickable/multi_pickable.rs
+++ b/arg_picker/src/pickable/multi_pickable.rs
@@ -5,13 +5,29 @@ use crate::{
 };
 
 /// Boundary check for multi-value positional parameters.
+///
+/// Determines whether a raw string marks the end of a multi-value
+/// parameter's input range.
 pub trait BoundaryCheck {
+    /// Returns `true` if `raw` indicates a boundary (i.e., the start of
+    /// a new parameter), stopping greedy collection.
     fn check_boundary(raw: &str) -> bool;
 }
 
 /// Trait for multi-value parameters.
+///
+/// Implementors define how a sequence of raw strings is converted into
+/// a single value, with an associated [`BoundaryCheck`] to control where
+/// collection stops.
 pub trait MultiPickableWithBoundary: Sized {
+    /// The boundary checker type that determines when to stop consuming
+    /// positional arguments.
     type Checker: BoundaryCheck;
+
+    /// Parse and collect multiple raw string values into `Self`.
+    ///
+    /// The caller should stop passing additional items once the
+    /// associated [`Checker`](Self::Checker) signals a boundary.
     fn pick_multi(raw: Vec<String>) -> PickerArgResult<Self>;
 }
 
diff --git a/arg_picker/src/value/vec_until.rs b/arg_picker/src/value/vec_until.rs
index 1b79641..04d87ce 100644
--- a/arg_picker/src/value/vec_until.rs
+++ b/arg_picker/src/value/vec_until.rs
@@ -21,6 +21,7 @@ pub struct VecUntil<T> {
 }
 
 impl<T> VecUntil<T> {
+    /// Consumes `self` and returns the underlying [`Vec<T>`].
     pub fn into_inner(self) -> Vec<T> {
         self.inner
     }