improve doc comments

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

internal/log/log.go

@@ -1,37 +1,49 @@
+/*
+Package log contains the singleton object and helper functions for facilitating logging within the syft library.
+*/
 package log
 
 import "github.com/anchore/syft/syft/logger"
 
+// Log is the singleton used to facilitate logging internally within syft
 var Log logger.Logger = &nopLogger{}
 
+// Errorf takes a formatted template string and template arguments for the error logging level.
 func Errorf(format string, args ...interface{}) {
 	Log.Errorf(format, args...)
 }
 
+// Error logs the given arguments at the error logging level.
 func Error(args ...interface{}) {
 	Log.Error(args...)
 }
 
+// Warnf takes a formatted template string and template arguments for the warning logging level.
 func Warnf(format string, args ...interface{}) {
 	Log.Warnf(format, args...)
 }
 
+// Warn logs the given arguments at the warning logging level.
 func Warn(args ...interface{}) {
 	Log.Warn(args...)
 }
 
+// Infof takes a formatted template string and template arguments for the info logging level.
 func Infof(format string, args ...interface{}) {
 	Log.Infof(format, args...)
 }
 
+// Info logs the given arguments at the info logging level.
 func Info(args ...interface{}) {
 	Log.Info(args...)
 }
 
+// Debugf takes a formatted template string and template arguments for the debug logging level.
 func Debugf(format string, args ...interface{}) {
 	Log.Debugf(format, args...)
 }
 
+// Debug logs the given arguments at the debug logging level.
 func Debug(args ...interface{}) {
 	Log.Debug(args...)
 }