Fix typo (exmaple to example) in README.md

Line 51 in the README.md had a typo.

README.md

@@ -48,7 +48,7 @@ const myCache = new NodeCache();
 - `errorOnMissing`: *(default: `false`)* en/disable throwing or passing an error to the callback if attempting to `.get` a missing or expired value.
 - `useClones`: *(default: `true`)* en/disable cloning of variables. If `true` you'll get a copy of the cached variable. If `false` you'll save and get just the reference.
 **Note:** `true` is recommended, because it'll behave like a server-based caching. You should set `false` if you want to save mutable objects or other complex types with mutability involved and wanted.
-_Here's a [simple code exmaple](https://runkit.com/mpneuried/useclones-example-83) showing the different behavior_
+_Here's a [simple code example](https://runkit.com/mpneuried/useclones-example-83) showing the different behavior_
 - `deleteOnExpire`: *(default: `true`)* whether variables will be deleted automatically when they expire.
 If `true` the variable will be deleted. If `false` the variable will remain. You are encouraged to handle the variable upon the event `expired` by yourself.