Add usage to readme

Also fix hardcoded name

README.md

@@ -22,3 +22,13 @@ running or however you want to do it.
 
 On first run the app will ask for all tokens/secrets from twitter, as well
 as the directory that you would like images to be downloaded to.
+
+## Usage
+
+```
+twimgarc - Download Images from a Twitter Stream
+    -count,-c=<num>        Pull the last <num> tweets
+    -force,-f              Download images even if the file already exists
+    -help ,-h              View this message
+    -verbose ,-v           Be chatty
+```

main.go

@@ -134,7 +134,7 @@ func PrintIfVerbose(val ...string) {
 }
 
 func PrintUsageAndExit() {
-	fmt.Println("twitstch - Download Images from a Twitter Stream")
+	fmt.Println(AppName + " - Download Images from a Twitter Stream")
 	fmt.Println("    -count,-c=<num>        Pull the last <num> tweets")
 	fmt.Println("    -force,-f              Download images even if the file already exists")
 	fmt.Println("    -help ,-h              View this message")