Fix broken link to docs in readme (#67)

The link [complete API documentation](https://labs.maptiler.com/maptiler-client-js) is not working (404 File not found).

Replace the link
https://labs.maptiler.com/maptiler-client-js -> https://docs.maptiler.com/client-js/

Author: kudlav

readme.md

@@ -44,7 +44,7 @@ npm install --save @maptiler/client
 ```
 
 # API documentation
-In addition to the details and examples provided in this readme, check out the [complete API documentation](https://labs.maptiler.com/maptiler-client-js).
+In addition to the details and examples provided in this readme, check out the [complete API documentation](https://docs.maptiler.com/client-js/).
 
 # Quick start
 ```ts