Clean up certain style choices on website's example documentation (#1616)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1616

This is based on a few comments earlier in the stack and my own discretion on what should change. But I went through all of the examples and changed the following:

* Only add code tick marks in a few cases where it would make sense. Things like `start` and `end`, `undefined` as a value, etc. There ends up not being that many after this. Previously, any property or value was tick marked even if it was more of a concept than actual code. **I replaced those cases with a link to their respective documentation as I feel like this keeps the indication that this is a keyword without labeling it as code**.
* Any reference to "element" was changed to "node"
* Capitalize words that follow a colon
* Run code examples through prettier for consistent style

Reviewed By: yungsters

Differential Revision: D54816609

fbshipit-source-id: 20ee925cf46bd1c519cc88bab9327321e926ac56

website-next/docs/styling/position.mdx

@@ -7,7 +7,7 @@ import Playground from '@site/src/components/Playground';
 # Position
 
 **Relative (default)**: This node is laid out according to the specified flow of the flex container it is apart of.
-That is, it particpates in the flexbox algorithm and will take up space within the container, unlike `absolute`.
+That is, it particpates in the flexbox algorithm and will take up space within the container, unlike absolute.
 Insets (`left`, `right`, `top`, `bottom`, etc) will offset the node from its normal position within its container.
 This node will always form a [containing block](https://developer.mozilla.org/en-US/docs/Web/CSS/Containing_block).
 
@@ -15,8 +15,7 @@ This node will always form a [containing block](https://developer.mozilla.org/en
 Absolute nodes do not take up space in its flex container and will not affect the position of
 its siblings. Insets will offset the node from its [containing block](https://developer.mozilla.org/en-US/docs/Web/CSS/Containing_block).
 
-
-**Static**: This node behaves like `relative` except it will ignore insets and will not
+**Static**: This node behaves like relative except it will ignore insets and will not
 form a [containing block](https://developer.mozilla.org/en-US/docs/Web/CSS/Containing_block).
 
 <Playground code={`<Layout config={{useWebDefaults: false}}>
@@ -24,13 +23,15 @@ form a [containing block](https://developer.mozilla.org/en-US/docs/Web/CSS/Conta
     style={{
       width: 200,
       height: 200,
-      padding: 10
+      padding: 10,
     }}>
     <Node
       style={{
         margin: 5,
         height: 50,
-        position: 'relative'
-      }}/>
+        top: 20,
+        position: 'relative',
+      }}
+    />
   </Node>
 </Layout>`} />