Improve Client CLI help readability (#2073)

Currently the CLI `-h/--help` commad output is almost unreadable as (for
some commands) it:
- doesn't provide a short brief of what the command does.
- doesn't separate the options description in smaller paragraphs.
- doesn't use a smart wrap strategy for lines longer than the number of
columns in the terminal.

Follow some pics taken with a 100 cols wide term

## Short help (./node -h)

### Before


![20231028-174531-grim](https://github.com/paritytech/polkadot-sdk/assets/8143589/11b62c3c-dcd5-43f4-ac58-f1b299e3f4b9)

### After


![20231028-175041-grim](https://github.com/paritytech/polkadot-sdk/assets/8143589/dc08f6fd-b287-40fb-8b33-71a185922104)


## Long help (./node --help)

### Before


![20231028-175257-grim](https://github.com/paritytech/polkadot-sdk/assets/8143589/9ebdc0ae-54ee-4760-b873-a7e813523cb6)

### After


![20231028-175155-grim](https://github.com/paritytech/polkadot-sdk/assets/8143589/69cbe5cb-eb2f-46a5-8ebf-76c0cf8c4bad)

---------

Co-authored-by: command-bot <>

substrate/client/cli/src/params/pruning_params.rs

@@ -24,6 +24,7 @@ use sc_service::{BlocksPruning, PruningMode};
 #[derive(Debug, Clone, Args)]
 pub struct PruningParams {
 	/// Specify the state pruning mode.
+	///
 	/// This mode specifies when the block's state (ie, storage)
 	/// should be pruned (ie, removed) from the database.
 	/// This setting can only be set on the first creation of the database. Every subsequent run
@@ -38,6 +39,7 @@ pub struct PruningParams {
 	pub state_pruning: Option<DatabasePruningMode>,
 
 	/// Specify the blocks pruning mode.
+	///
 	/// This mode specifies when the block's body (including justifications)
 	/// should be pruned (ie, removed) from the database.
 	/// Possible values: