Update b5.impls-and-traits.md (#68)

* Update b5.impls-and-traits.md

* Update b5.impls-and-traits.md

Author: JeukHwang

content/en/docs/b5.impls-and-traits.md

@@ -33,10 +33,6 @@ fn main() {
 }
 
 // ⭐️ Implementation must appear in the same crate as the self type
-
-// 💡 And also in Rust, new traits can be implemented for existing types even for types like i8, f64 and etc.
-// Same way existing traits can be implemented for new types you are creating.
-// But we can not implement existing traits into existing types.
 ```
 
 ## Impls & traits, without default methods
@@ -67,6 +63,9 @@ fn main() {
 }
 
 // 🔎 Other than functions, traits can contain constants and types.
+
+// 💡 And also in Rust, new traits can be implemented for existing types even for types like i8, f64 and etc.
+// Same way existing traits can be implemented for new types you are creating.
 ```
 
 ## Impls, traits & default methods
@@ -122,13 +121,13 @@ fn main() {
 trait From<T> {
     fn from(T) -> Self;
 }
-    impl From<u8> for u16 {
-        //...
-    }
-    impl From<u8> for u32{
-        //...
-    }
-    
+
+impl From<u8> for u16 {
+    //...
+}
+impl From<u8> for u32{
+    //...
+}
 // Should specify after the trait name like generic functions
 ```
 
@@ -139,13 +138,13 @@ trait Person {
     fn full_name(&self) -> String;
 }
 
-    trait Employee : Person { // Employee inherits from person trait
-      fn job_title(&self) -> String;
-    }
+trait Employee : Person { // Employee inherits from person trait
+  fn job_title(&self) -> String;
+}
 
-    trait ExpatEmployee : Employee + Expat { // ExpatEmployee inherits from Employee and Expat traits
-      fn additional_tax(&self) -> f64;
-    }
+trait ExpatEmployee : Employee + Expat { // ExpatEmployee inherits from Employee and Expat traits
+  fn additional_tax(&self) -> f64;
+}
 ```
 
 ## Trait objects
@@ -163,20 +162,22 @@ trait GetSound {
 struct Cat {
     sound: String,
 }
-    impl GetSound for Cat {
-        fn get_sound(&self) -> String {
-            self.sound.clone()
-        }
+
+impl GetSound for Cat {
+    fn get_sound(&self) -> String {
+        self.sound.clone()
     }
+}
 
 struct Bell {
     sound: String,
 }
-    impl GetSound for Bell {
-        fn get_sound(&self) -> String {
-            self.sound.clone()
-        }
+
+impl GetSound for Bell {
+    fn get_sound(&self) -> String {
+        self.sound.clone()
     }
+}
 
 
 fn make_sound<T: GetSound>(t: &T) {