fix: readme fmt

Signed-off-by: Carlos Alexandro Becker <caarlos0@gmail.com>

README.md

@@ -17,11 +17,11 @@ import (
 	"fmt"
 	"time"
 
-  // if using go modules
-  "github.com/caarlos0/env/v6"
+	// if using go modules
+	"github.com/caarlos0/env/v6"
 
-  // if using dep/others
-  "github.com/caarlos0/env"
+	// if using dep/others
+	"github.com/caarlos0/env"
 )
 
 type config struct {
@@ -135,22 +135,25 @@ type config struct {
 ## From file
 
 The `env` tag option `file` (e.g., `env:"tagKey,file"`) can be added
-to in order to indicate that the value of the variable shall be loaded from a file. The path of that file is given 
+to in order to indicate that the value of the variable shall be loaded from a file. The path of that file is given
 by the environment variable associated with it
 Example below
 
 ```go
 package main
+
 import (
-    "fmt"
-    "time"
-    "github.com/caarlos0/env"
+	"fmt"
+	"time"
+	"github.com/caarlos0/env"
 )
+
 type config struct {
-    Secret       string   `env:"SECRET,file"`
-    Password     string   `env:"PASSWORD,file" envDefault:"/tmp/password"`
-    Certificate  string   `env:"CERTIFICATE,file" envDefault:"${CERTIFICATE_FILE}" envExpand:"true"`
+	Secret       string   `env:"SECRET,file"`
+	Password     string   `env:"PASSWORD,file" envDefault:"/tmp/password"`
+	Certificate  string   `env:"CERTIFICATE,file" envDefault:"${CERTIFICATE_FILE}" envExpand:"true"`
 }
+
 func main() {
 	cfg := config{}
 	if err := env.Parse(&cfg); err != nil {
@@ -165,10 +168,10 @@ func main() {
 $ echo qwerty > /tmp/secret
 $ echo dvorak > /tmp/password
 $ echo coleman > /tmp/certificate
- 
+
 $ SECRET=/tmp/secret  \
-  CERTIFICATE_FILE=/tmp/certificate \
-  go run main.go
+	CERTIFICATE_FILE=/tmp/certificate \
+	go run main.go
 {Secret:qwerty Password:dvorak Certificate:coleman}
 ```