improve readme

Author: marianobrc

README.md

@@ -29,23 +29,24 @@ DOWNLOADER_MIDDLEWARES = {
 ```
 ## Usage
 
-Use the scrapy_proxycrawl.ProxyCrawlRequest instead of the scrapy built-in Request:
+Use the scrapy_proxycrawl.ProxyCrawlRequest instead of the scrapy built-in Request.
+The scrapy_proxycrawl.ProxyCrawlRequest accepts additional arguments, used in Proxy Crawl API:
 
 ```python
 from scrapy_proxycrawl import ProxyCrawlRequest
 
 yield ProxyCrawlRequest(
-    url,
+    "http://target-url",
     callback=self.parse_result
     device='desktop',
     country='US',
-    page_wait=8000,
+    page_wait=1000,
     ajax_wait=True,
     dont_filter=True
 )
 ```
-The scrapy_proxycrawl.ProxyCrawlRequest accepts additional arguments, used in Proxy Crawl API.
-The request and response will be handled by the middleware, switching the urls automatically.
+
+The target url will be replaced with proxy crawl url and parameters will be encoded into the url by the middleware automatically.
 
 
 If you have questions or need help using the library, please open an issue or [contact us](https://proxycrawl.com/contact).