Finish all core libraries docs (#253)

* Doc

* Doc

doc/src/user/cli/state.md

@@ -111,7 +111,7 @@ darwinia --chain darwinia-dev.json.export --alice --tmp
 2022-08-25 15:32:41 💤 Idle (0 peers), best: #4 (0xfd60…b2f2), finalized #2 (0x6027…c86e), ⬇ 14 B/s ⬆ 0
 ```
 
-With the `--simple-governance` flag, you could perform a runtime upgrade test though sudo or council locally.
+With the `--simple-governance` flag, you could perform a runtime upgrade test through sudo or council locally.
 
 It's a really useful testing tool.
 

lib/core/src/check/features/mod.rs

@@ -1,3 +1,5 @@
+//! Cargo features checker.
+
 #[cfg(test)] mod test;
 
 // crates.io

lib/core/src/check/mod.rs

@@ -1,8 +1,4 @@
-//! A series of Substrate checkers.
-//!
-//! CI setup examples: <https://github.com/darwinia-network/darwinia-common/blob/main/.github/workflows/checks.yml>
+//! A series of checkers.
 
-/// Features checker.
 pub mod features;
-/// Runtime checkers.
 pub mod runtime;

lib/core/src/check/runtime.rs

@@ -1,3 +1,5 @@
+//! Substrate-like runtime checker.
+
 // std
 use std::{
 	fmt::{Debug, Write},
@@ -10,8 +12,8 @@ use submetadatan::{
 	StorageEntryMetadata,
 };
 
-/// Compare the nodes' runtime versions.
-/// If there is no difference, return `None`.
+/// Fetch two nodes' runtime versions through their HTTP RPC endpoints.
+/// Compare the versions, then return the differences in markdown diff style.
 pub async fn check_version(a_uri: &str, b_uri: &str) -> Result<Option<String>> {
 	const E_WRITE_TO_STRING_NEVER_FAILS: &str = "[core::check] write to string never fails; qed";
 
@@ -39,7 +41,8 @@ pub async fn check_version(a_uri: &str, b_uri: &str) -> Result<Option<String>> {
 	Ok(Some(result))
 }
 
-/// Compare the nodes' runtime storages.
+/// Fetch two nodes' runtime storage through their HTTP RPC endpoints.
+/// Compare the storage, then return the differences in markdown diff style.
 pub async fn check_storage(
 	a_uri: &str,
 	b_uri: &str,

lib/core/src/http/mod.rs

@@ -6,5 +6,5 @@ use std::sync::Arc;
 use once_cell::sync::Lazy;
 use reqwest::Client;
 
-/// Global HTTP client.
+/// Subalfred's global HTTP client.
 pub static CLIENT: Lazy<Arc<Client>> = Lazy::new(|| Arc::new(Client::new()));

lib/core/src/jsonrpc/http/mod.rs

@@ -8,7 +8,7 @@ use serde::{de::DeserializeOwned, Serialize};
 use super::*;
 use crate::{http::CLIENT, prelude::*};
 
-/// Send the JSONRPC through the [`CLIENT`] with the given JSON.
+/// Send a JSONRPC request through the [`CLIENT`].
 pub async fn send<S, D>(uri: &str, s: &S) -> Result<Response<D>>
 where
 	S: Serialize,

lib/core/src/jsonrpc/ws/mod.rs

@@ -227,7 +227,7 @@ impl Default for Initializer {
 	}
 }
 
-/// Ws instance.
+/// A Ws instance.
 ///
 /// Use this to interact with the server.
 pub struct Ws {
@@ -395,13 +395,13 @@ enum Call {
 	Batch(RawCall<BatchNotifier>),
 }
 
-/// A single request object.
-/// `id`: Request Id.
+// A single request object.
+// `id`: Request Id.
 //
-/// Or
-///
-/// A batch requests object to send several request objects simultaneously.
-/// `id`: The first request's id.
+// Or
+//
+// A batch requests object to send several request objects simultaneously.
+// `id`: The first request's id.
 #[derive(Debug)]
 struct RawCall<N> {
 	id: Id,