Add explanations to use exact url flag to Readme

README.md

@@ -26,15 +26,16 @@ It will download the last version of every file present on Wayback Machine to `.
 
 ## Advanced Usage
 
-Usage: wayback_machine_downloader http://example.com
+	Usage: wayback_machine_downloader http://example.com
 
-Download an entire website from the Wayback Machine.
+	Download an entire website from the Wayback Machine.
 
 	Optional options:
 	    -d, --directory PATH             Directory to save the downloaded files into
 					     Default is ./websites/ plus the domain name
 	    -f, --from TIMESTAMP             Only files on or after timestamp supplied (ie. 20060716231334)
 	    -t, --to TIMESTAMP               Only files on or before timestamp supplied (ie. 20100916231334)
+	    -e, --exact_url                  Download only the url provied and not the full site
 	    -o, --only ONLY_FILTER           Restrict downloading to urls that match this filter
 					     (use // notation for the filter to be treated as a regex)
 	    -x, --exclude EXCLUDE_FILTER     Skip downloading of urls that match this filter
@@ -43,11 +44,12 @@ Download an entire website from the Wayback Machine.
 	    -c, --concurrency NUMBER         Number of multiple files to dowload at a time
 					     Default is one file at a time (ie. 20)
 	    -p, --maximum-snapshot NUMBER    Maximum snapshot pages to consider (Default is 100)
-					     Count an average of 150,000 snapshots per page 
-	    -l, --list                       Only list file urls in a JSON format with the archived timestamps, won't download anything.
+					     Count an average of 150,000 snapshots per page
+	    -l, --list                       Only list file urls in a JSON format with the archived timestamps, won't download anything
 	    -v, --version                    Display version
 
 
+
 	    
 ## Specify directory to save files to
 
@@ -80,6 +82,17 @@ Wayback Machine Downloader will then fetch only file versions on or before the t
 Example:
 
     wayback_machine_downloader http://example.com --to 20100916231334
+
+## Exact Url
+
+	-e, --exact_url 
+
+Optional. If you want to retrieve only the file matching exactly the url provided, you can use this flag. It will avoid downloading anything else.
+
+For example, if you only want to download only the html homepage file of example.com:
+
+    wayback_machine_downloader http://example.com --exact_url 
+
 
 ## Only URL Filter