#53 Update CLI usage message in apg.go

The usage message has been updated in apg.go to improve its clarity and usefulness. Changes include displaying the version number dynamically, providing the project's GitHub link, changing the term 'options' to 'flags', and more precise terminology in descriptions. Also, formatting has been adjusted to improve readability.

cmd/apg/apg.go

@@ -72,13 +72,15 @@ func main() {
 // usage is used by the flag package to display the CLI usage message
 func usage() {
 	// Usage text
-	const ut = `apg-go // A "Automated Password Generator"-clone
-Copyleft (c) 2021-2023 Winni Neessen
+	const ut = `apg-go v` +
+		apg.VERSION + "\n" +
+		`A OSS "Automated Password Generator"-clone -- https://github.com/wneessen/apg-go/
+Created 2021-2023 by Winni Neessen (MIT licensed)
 
 apg [-a <algo>] [-m <length>] [-x <length>] [-L] [-U] [-N] [-S] [-H] [-C]
     [-l] [-M mode] [-E char_string] [-n num_of_pass] [-v] [-h] [-t]
 
-Options:
+Flags:
     -a ALGORITH          Choose the password generation algorithm (Default: 1)
                           - 0: pronounceable password generation (koremutake syllables)
                           - 1: random password generation according to password modes/flags
@@ -87,7 +89,7 @@ Options:
     -f LENGTH            Fixed length of the password to be generated (Ignores -m and -x)
     -n NUMBER            Amount of password to be generated (Default: 6)
     -E CHARS             List of characters to be excluded in the generated password
-    -M [LUNSHClunshc]    New style password parameters
+    -M [LUNSHClunshc]    New style password flags
                           - Note: new-style flags have higher priority than any of the old-style flags
     -L                   Toggle lower case characters in passwords (Default: on)
     -U                   Toggle upper case characters in passwords (Default: on)
@@ -100,8 +102,7 @@ Options:
     -p                   Check the HIBP database if the generated passwords was found in a leak before (Default: off)
                           - Note: this feature requires internet connectivity
     -h                   Show this help text
-    -v                   Show version string
+    -v                   Show version string`
 
-`
-	_, _ = os.Stderr.WriteString(ut)
+	_, _ = os.Stderr.WriteString(ut + "\n\n")
 }