Update README.md

README.md

@@ -11,6 +11,6 @@ This map was created by Daniel Somerville and used with his permission. You can
 ## Description
 This is a library to help you create maps for D&D and other tabletop RPGs. It uses JavaScript and HTML5 canvas. Look at [battle-map-explorer-dev.js](https://github.com/byronknoll/battle-map-explorer/blob/master/battle-map-explorer-dev.js) and [example-map.html](https://github.com/byronknoll/battle-map-explorer/blob/master/example-map.html) to get started. The maps should work across all modern web browsers, operating systems, smart phones, and tablets.
 
-Creating a map involves manually tracing the coordinates of walls and obstacles. The coordinates match the pixel count of the background image (with the origin in the top-left). One way to find the coordinates is to load an image using this library (without any walls), navigate to a place you want to record, and press 'space'. This will log the coordinates at the crosshair into your browser's developer console. You can press '/' to adjust the movement speed to help fine-tune coordinates.
+Creating a map involves manually tracing the coordinates of walls and obstacles. The coordinates match the pixel positions of the background image (with the origin in the top-left). One way to find the coordinates is to load an image using this library (without any walls), navigate to a place you want to record, and press 'space'. This will log the coordinates at the crosshair into your browser's developer console. You can press '/' to adjust the movement speed to help fine-tune coordinates.
 
 Contact me at [email protected] if you have any questions or feature requests.