Text fixes

Author: whit0694

exercises/luhn-from/HINTS.md

@@ -4,6 +4,6 @@ Before doing this exercise you should probably do the original Luhn exercise.
 
 `exercism fetch rust luhn`
 
-In the original Luhn exercise you only validated strings, but the Luhn algorithm can be applied integers as well.
+In the original Luhn exercise you only validated strings, but the Luhn algorithm can be applied to integers as well.
 
-In this exercise you'll use the [From trait](https://doc.rust-lang.org/std/convert/trait.From.html) to convert strings, strs and unsigned integers into a Struct that perfoms the validation.
+In this exercise you'll use the [From trait](https://doc.rust-lang.org/std/convert/trait.From.html) to convert strings, strs and unsigned integers into a Struct that performs the validation.

exercises/luhn-trait/HINTS.md

@@ -5,12 +5,12 @@ Before doing this exercise you should probably do the original Luhn exercise and
 - `exercism fetch rust luhn`
 - `exercism fetch rust luhn-from`
 
-In the original Luhn exercise you only validated strings, but the Luhn algorithm can be applied integers as well.
+In the original Luhn exercise you only validated strings, but the Luhn algorithm can be applied to integers as well.
 
-In Luhn From you implemented a From trait, which also required you to create a Luhn struct. 
+In Luhn From you implemented a From trait, which also required you to create a Luhn struct.
 
 Instead of creating a Struct just to perform the validation, what if you you validated the primitives (i.e, String, u8, etc.) themselves?
 
-In this exercise you'll create and implement a custom [trait](https://doc.rust-lang.org/book/traits.html) that performs the validation
+In this exercise you'll create and implement a custom [trait](https://doc.rust-lang.org/book/traits.html) that performs the validation.
 
 Note: It is [not idiomatic Rust to implement traits on on primitives](https://doc.rust-lang.org/book/traits.html#rules-for-implementing-traits). In this exercise we're showing something that you _can_ do, not something you _should_ do. If you find yourself implementing traits on primitives, perhaps you have a case of [Primitive Obsession](http://wiki.c2.com/?PrimitiveObsession).