chore: add example to readme

README.md

@@ -29,7 +29,23 @@ In stable rust channel you can use only connection interface, but if you use nig
 
 ## Usage
 
-See examples directory.
+```rust
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // create pool to our database
+    let pool = create_postgres_pool();
+    // initialize persistence
+    let persistence = ood_persistence::r2d2_postgres::new(&pool);
+    // get connection to database
+    let mut conn = persistence.get_connection()?;
+    // we can query something
+    let res: i32 = conn.inner().query_one("select 1", &[])?.get(0);
+    assert_eq!(res, 1);
+
+    Ok(())
+}
+```
+
+See examples directory for more information.
 
 
 ## Contributors

src/lib.rs

@@ -25,7 +25,27 @@
 //!
 //! ## Usage
 //!
-//! See examples directory.
+//! ```rust
+//! fn main() -> Result<(), Box<dyn std::error::Error>> {
+//!     // create pool to our database
+//!     let pool = create_postgres_pool();
+//!     // initialize persistence
+//!     let persistence = ood_persistence::r2d2_postgres::new(&pool);
+//!     // get connection to database
+//!     let mut conn = persistence.get_connection()?;
+//!     // we can query something
+//!     let res: i32 = conn.inner().query_one("select 1", &[])?.get(0);
+//!     assert_eq!(res, 1);
+//!
+//!     Ok(())
+//! }
+//! ```
+//!
+//! See examples directory for more information.
+//!
+//! ## Contributors
+//!
+//! [pleshevskiy](https://github.com/pleshevskiy) (Dmitriy Pleshevskiy) – creator, maintainer.
 //!
 #![forbid(unsafe_code, non_ascii_idents)]
 #![deny(clippy::pedantic)]