durableMap

durableMap is in-memory, durable storage optimized for ( write-heavy, read-heavy )

Why need to DurableMap ??

it is a concurrent hashMap using NonBlocking wal engine for persist to disk it avoid any loss data

Example

```rust

#[tokio::main] async fn main() {

 // Optimized for write concurrent (API is same) 
 // let dl1 = WConcurrentStorage::<Document>::open("tester".to_owned(), 1000).await;

 // Optimized for read concurrent
 let dl = RConcurrentStorage::<Document>::open("tester".to_owned(), 1000).await;

     for elem in 0..50_000 {
         let _ = dl.insert_entry(format!("{}", elem), 
                                 Document::new()).await;

     }

}

#[derive(Serialize, Deserialize, Clone)] struct Document { funame: String, age: i32, } impl Document { pub fn new() -> Self { Document { funame: String::from("DanyalMhai@gmail.com"), age: 24, } } }

```