Update 'README.md'

README.md

@@ -1,3 +1,41 @@
 # wafredir
 
 HTTP redirect builder for FortiWeb WAFs.  Configure your WAF from a spreadsheet.  
+
+### Build
+
+1. Install Go from https://golang.org
+2. Open a terminal from this directory and run the command:
+
+```shell
+go build .
+```
+
+### Usage
+
+Arguments of wafredir:
+  -action string
+        action can be either 'config' or 'test'.  'config' will read the input csv file and generate FortiOS compliant configuration to create redirection policies.  'test' will read the input csv file and validate that the redirects are actually working by making requests 
+at the source URL and validating a redirect to the destination URL actually occurs. (default "config")
+  -concurrentReq int
+        only used with the action 'test'.  Determines the maximum number concurrent HTTP GET requests which can be in flight at any given time. (default 8)
+  -csvfile string
+        path to an input csv file.  The first column of the file should be the source URL, the second column of the file should be the destination URL, and the third column should be the status code (for example 301 or 302). (default "redirects.csv")
+
+### Example input csv
+
+The first column is the source URL, the second column is the destination URL, the third column is the redirect type, must be either 301 or 302.
+
+```csv
+http://myoldsite.com/boomer,https://mynewsite.io/zoomer,301
+https://myoldblog.net/blog/post/1,https://mynewblog.ru/cykablyat,302
+http://mysite.org,https://yoursite.net/referral/mysite,301
+```
+
+### Example output of config mode
+
+```txt
+http://myoldsite.com/boomer,https://mynewsite.io/zoomer,301
+https://myoldblog.net/blog/post/1,https://mynewblog.ru/cykablyat,302
+http://mysite.org,https://yoursite.net/referral/mysite,301
+```