Add some comments

Signed-off-by: Cosmin Cojocar <cosmin.cojocar@gmx.ch>

issue.go

@@ -131,6 +131,7 @@ func (c Score) String() string {
 	return "UNDEFINED"
 }
 
+// codeSnippet extracts a code snippet based on the ast reference
 func codeSnippet(file *os.File, start int64, end int64, n ast.Node) (string, error) {
 	if n == nil {
 		return "", fmt.Errorf("invalid AST node provided")

output/formatter.go

@@ -322,6 +322,7 @@ func highlight(t string, s gosec.Score) string {
 	}
 }
 
+// printCodeSnippet prints the code snippet from the issue by adding a marker to the affected line
 func printCodeSnippet(issue *gosec.Issue) string {
 	scanner := bufio.NewScanner(strings.NewReader(issue.Code))
 	var buf bytes.Buffer