docs: fix theme link. Fixes frontend-collective#248

Author: fritz-c

README.md

@@ -99,7 +99,7 @@ Using the `theme` prop along with an imported theme module, you can easily overr
 |:--------:|:--------:|
 |**File Explorer**|**Full Node Drag**|
 |react-sortable-tree-theme-file-explorer|react-sortable-tree-theme-full-node-drag|
-|[Github](https://github.com/fritz-c/react-sortable-tree-theme-file-explorer) \| [NPM](https://www.npmjs.com/package/react-sortable-tree-theme-file-explorer)|[Github](https://github.com/fritz-c/react-sortable-tree-theme-full-node-drag) \| [NPM](https://www.npmjs.com/package/react-sortable-tree-full-node-drag)|
+|[Github](https://github.com/fritz-c/react-sortable-tree-theme-file-explorer) \| [NPM](https://www.npmjs.com/package/react-sortable-tree-theme-file-explorer)|[Github](https://github.com/fritz-c/react-sortable-tree-theme-full-node-drag) \| [NPM](https://www.npmjs.com/package/react-sortable-tree-theme-full-node-drag)|
 
 **Help Wanted** - As the themes feature has just been enabled, there are very few (only _two_ at the time of this writing) theme modules available. If you've customized the appearance of your tree to be especially cool or easy to use, I would be happy to feature it in this readme with a link to the Github repo and NPM page if you convert it to a theme. You can use my [file explorer theme repo](https://github.com/fritz-c/react-sortable-tree-theme-file-explorer) as a template to plug in your own stuff.