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.

1 files changed, 1 insertions, 0 deletions

diff --git a/mingling_core/src/renderer/structural/error.rs b/mingling_core/src/renderer/structural/error.rs
index a7fbc75..63ded81 100644
--- a/mingling_core/src/renderer/structural/error.rs
+++ b/mingling_core/src/renderer/structural/error.rs
@@ -9,6 +9,7 @@ pub struct StructuralRendererSerializeError {
 }
 
 impl StructuralRendererSerializeError {
+    /// Creates a new `StructuralRendererSerializeError` with the given error message.
     #[must_use]
     pub fn new(error: String) -> Self {
         Self { error }