chore: Update README.md to fix incorrect inlineSize/blockSize explanation.

fixes #104 

See:
- [uRO code](https://github.com/ZeeCoder/use-resize-observer/blob/master/src/index.ts#L118-L119)
- [MDN example](https://developer.mozilla.org/en-US/docs/Web/API/ResizeObserverEntry#examples)

Author: ZeeCoder

README.md

@@ -56,8 +56,8 @@ npm install use-resize-observer --save-dev
 | Name   | Type                    | Description                                    |
 | ------ | ----------------------- | ---------------------------------------------- |
 | ref    | RefCallback             | A callback to be passed to React's "ref" prop. |
-| width  | undefined | number | The width (or "blockSize") of the element.     |
-| height | undefined | number | The height (or "inlineSize") of the element.   |
+| width  | undefined | number | The width (or "inlineSize") of the element.     |
+| height | undefined | number | The height (or "blockSize") of the element.   |
 
 ## Basic Usage