change a method name according to code style, register method

Author: Roman Suvorov

Diff for: internal/transformations/base64encode.go

@@ -7,7 +7,7 @@ import (
 	"encoding/base64"
 )
 
-func base64Encode(data string) (string, bool, error) {
+func base64encode(data string) (string, bool, error) {
 	src := []byte(data)
 
 	return base64.StdEncoding.EncodeToString(src), true, nil

Diff for: internal/transformations/transformations.go

@@ -30,6 +30,7 @@ func GetTransformation(name string) (plugintypes.Transformation, error) {
 func init() {
 	Register("base64Decode", base64decode)
 	Register("base64DecodeExt", base64decodeext)
+	Register("base64Encode", base64encode)
 	Register("cmdLine", cmdLine)
 	Register("compressWhitespace", compressWhitespace)
 	Register("cssDecode", cssDecode)