chore(ci): enforce rustdoc warnings as errors

Add a docs step to CI with RUSTDOCFLAGS='-D warnings'.

Also fix rustdoc issues uncovered by the gate (ambiguous intra-doc links and generic type markdown).

Author: WendellXY

.github/workflows/rust.yml

@@ -32,5 +32,12 @@ jobs:
       - name: Build
         run: cargo build --workspace --all-targets --verbose
 
+      - name: Doc (warnings as errors)
+        env:
+          RUSTDOCFLAGS: "-D warnings"
+        run: |
+          cargo doc -p langcodec --no-deps
+          cargo doc -p langcodec-cli --lib --no-deps
+
       - name: Test
         run: cargo test --workspace --all-targets --verbose

langcodec-cli/src/transformers/langcodec_resource_array.rs

@@ -1,6 +1,6 @@
 use std::fs;
 
-/// Transform a langcodec::Resource array JSON file to a Vec<Resource>.
+/// Transform a `langcodec::Resource` array JSON file to a `Vec<langcodec::Resource>`.
 /// This format is a direct representation of langcodec::Resource objects in JSON.
 pub fn transform(input: String) -> Result<Vec<langcodec::Resource>, String> {
     // Read the file content

langcodec/src/error.rs

@@ -5,7 +5,7 @@
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
-/// Stable machine-readable category for [`Error`].
+/// Stable machine-readable category for [`enum@Error`].
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case")]
 pub enum ErrorCode {
@@ -39,7 +39,7 @@ pub struct ErrorContext {
     pub candidates: Vec<String>,
 }
 
-/// Serializable structured representation of an [`Error`].
+/// Serializable structured representation of an [`enum@Error`].
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct StructuredError {
     pub code: ErrorCode,