docs: Enhance module documentation across various files for clarity a… (#62)

* docs: Enhance module documentation across various files for clarity and completeness

* fix: Remove unnecessary blank line in build.rs for cleaner code

* docs: Update documentation to improve clarity and consistency in code comments

src/errors.rs

@@ -1,3 +1,12 @@
+//! Error types used throughout the scanner.
+//!
+//! [`NyxError`] wraps I/O, TOML parse, SQLite, tree-sitter, and connection-pool
+//! errors into a single enum. [`NyxResult<T>`] is the standard return type alias.
+//!
+//! [`ConfigError`] and [`ConfigErrorKind`] carry structured config-validation
+//! diagnostics (section, field, message, kind) so callers can format them
+//! consistently without ad-hoc string matching.
+
 use serde::Serialize;
 use serde::de::StdError;
 use std::fmt;