fix(try_from_into): Update description (rust-lang#584)

Description update

exercises/conversions/try_from_into.rs

@@ -15,12 +15,12 @@ struct Color {
 
 // Your task is to complete this implementation
 // and return an Ok result of inner type Color.
-// You need create implementation for a tuple of three integer,
-// an array of three integer and slice of integer.
+// You need to create an implementation for a tuple of three integers,
+// an array of three integers and a slice of integers.
 //
-// Note, that implementation for tuple and array will be checked at compile-time,
-// but slice implementation need check slice length!
-// Also note, that chunk of correct rgb color must be integer in range 0..=255.
+// Note that the implementation for tuple and array will be checked at compile time,
+// but the slice implementation needs to check the slice length!
+// Also note that correct RGB color values must be integers in the 0..=255 range.
 
 // Tuple implementation
 impl TryFrom<(i16, i16, i16)> for Color {