📝 Align API docs with updated interface template

docs/api/queue-config.md

@@ -0,0 +1,85 @@
+---
+name: queue-config
+group: api
+category: config
+update-time: 20260512
+description: Build a serializable queue wrapper config for configured synchronous loggers.
+key-word:
+    - queue
+    - config
+    - json
+    - public
+---
+
+## Queue-config
+
+Create a `QueueConfig` value for config-driven synchronous queue wrapping. This API is used inside `LoggerConfig` when the final runtime sink should be wrapped by a bounded synchronous queue.
+
+### Interface
+
+```moonbit
+pub fn QueueConfig::new(
+  max_pending : Int,
+  overflow~ : QueueOverflowPolicy = QueueOverflowPolicy::DropNewest,
+) -> QueueConfig {}
+```
+
+#### input
+
+- `max_pending : Int` - Queue capacity used by the configured queue wrapper.
+- `overflow : QueueOverflowPolicy` - Overflow strategy for full queues.
+
+#### output
+
+- `QueueConfig` - Queue configuration value suitable for `LoggerConfig` or JSON serialization helpers.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- This config is used by `build_logger(...)` and `parse_and_build_logger(...)` when `queue` is present in `LoggerConfig`.
+- It configures the synchronous `QueuedSink`, not the async adapter package.
+- The queue remains explicit and drain-based.
+- Overflow behavior is limited to the supported queue policies.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need Config-driven Bounded Queueing
+
+When runtime queue wrapping should be described as config:
+```moonbit
+let queue = QueueConfig::new(32, overflow=QueueOverflowPolicy::DropOldest)
+let config = LoggerConfig::new(queue=Some(queue))
+```
+
+In this example, the queue policy is expressed as data and later consumed by the runtime builder.
+
+#### When Need JSON Export For Tooling
+
+When queue policy should be exported or persisted:
+```moonbit
+println(stringify_queue_config(QueueConfig::new(8)))
+```
+
+In this example, the queue config is converted into a stable JSON representation.
+
+### Error Case
+
+e.g.:
+- If `max_pending` is too small, configured runtime drops may happen frequently under bursty load.
+
+- If queue config is omitted from `LoggerConfig`, no synchronous queue wrapper is added.
+
+### Notes
+
+Notes are here.
+
+1. This API is for config-driven queue wrapping, not `bitlogger_async`.
+
+2. Use `Logger::with_queue(...)` when you want code-side queue composition instead of config.
+
+3. Pair with `stringify_queue_config(...)` when inspecting generated config output.
+
+4. Queue capacity policy should be chosen based on expected burst size and acceptable loss behavior.