feat(format_me): add new exercise for rust exams

subjects/format_me/README.md

@@ -0,0 +1,76 @@
+## format_me
+
+### Instructions
+
+In this exercise you will implement the trait `Display` for the structure `Park` and the enum `ParkType`.
+
+Here are the public fields and possible variants for the two types:
+
+- `Park`:
+  - `name` as `String`
+  - `park_type` as `ParkType`
+  - `address` as `String`
+  - `cap` as `String`
+  - `state` as `String`
+- `ParkType`:
+  - `Garden`
+  - `Forest`
+  - `Playground`
+
+### Expected Functions and Structures
+
+```rust
+use std::fmt;
+
+pub struct Park {}
+  
+pub enum ParkType {}
+
+impl fmt::Display for Park {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {}
+}
+
+impl fmt::Display for ParkType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {}
+}
+```
+
+### Usage
+
+Here is a program to test your function:
+
+```rust
+use format_me::*;
+
+fn main() {
+    println!(
+        "{}",
+        Park {
+            name: "Les Tuileries".to_string(),
+            park_type: ParkType::Garden,
+            address: "Pl. de la Concorde".to_string(),
+            cap: "75001".to_string(),
+            state: "France".to_string()
+        }
+    );
+    println!(
+        "{}",
+        Park {
+            name: "".to_string(),
+            park_type: ParkType::Playground,
+            address: "".to_string(),
+            cap: "".to_string(),
+            state: "".to_string()
+        }
+    );
+}
+```
+
+And its output
+
+```console
+$ cargo run
+garden - Les Tuileries, Pl. de la Concorde, 75001 - France
+playground - No name, No address, No cap - No state
+$
+```