feat: improve logging on startup

Update the exporter logging on startup to include the exporter version,
the path to the fail2ban socket, and whether basic-auth is enabled or not.
Fix code printing error messages on invalid CLI parameters to correct line
breaks and correctly print the "usage" information.

src/collector/textfile/collector.go

@@ -25,7 +25,7 @@ func NewCollector(appSettings *cfg.AppSettings) *Collector {
 		fileMap:    make(map[string]*fileData),
 	}
 	if collector.enabled {
-		log.Printf("collector.textfile directory: %s", collector.folderPath)
+		log.Printf("reading textfile metrics from: %s", collector.folderPath)
 	}
 	return collector
 }