minor docs improvements (#2279)

* format "The `to` prop" in async-animations.mdx

* fix spelling of "targetting"/"targetted" in targets.mdx

Author: btoo

docs/app/routes/docs.advanced.async-animations.mdx

@@ -59,7 +59,7 @@ export default function MyComponent() {
 }
 ```
 
-## The to prop
+## The `to` prop
 
 If you've read any of the `component` pages, you'll know we accept a `to` prop, it's typically used as an object,
 but alternatively, you can also use an array (chaining the animations) or a function (writing an animation script).

docs/app/routes/docs.concepts.targets.mdx

@@ -20,7 +20,7 @@ export const meta = formatFrontmatterToRemixMeta(frontmatter)
 ## What is a target?
 
 When a target is discussed it is sometimes in reference to the platform, e.g. you create a client side react application
-chances are it's targetted at the browser. However, if you write a server-side application then you're targetting node.
+chances are it's targeted at the browser. However, if you write a server-side application then you're targeting node.
 Whilst `react-spring` does support the targets `web` and `native` and _can_ be server-side rendered. This is not the type
 of target we're referring to.