Auto detect input language as default

Author: Jay Trees

README.md

@@ -65,7 +65,7 @@ foreach ($translations as $translation) {
 | param               | Description                                                                                                                                                                                                                                                                                                                                                                                                               |
 |---------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | $text               | Text to be translated. Only UTF8-encoded plain text is supported. The parameter may be specified as an Array and translations are returned in the same order as they are requested. Each of the array values may contain multiple sentences. Up to 50 texts can be sent for translation in one request.                                                                                                            |
-| $sourceLang         | Language of the text to be translated. <br>default: de                                                                                                                                                                                                                                                                                                                                                                                   |
+| $sourceLang         | Language of the text to be translated. <br>default: "" (DeepL will auto-detect)                                                                                                                                                                                                                                                                                                                                                                                   |
 | $targetLang         | The language into which the text should be translated. <br> default: en                                                                                                                                                                                                                                                                                                                                                                    |
 | $tagHandling        | Sets which kind of tags should be handled. Options currently available: "xml"                                                                                                                                                                                                                                                                                                                                             |
 | $ignoreTags         | Array of XML tags that indicate text not to be translated. <br> default: null                                                                                                                                                                                                                                                                                                                                                  |
@@ -110,7 +110,7 @@ You can now check how much you translate, as well as the limit:
 $usageArray = $deepl->usage();
 
 echo 'You have used '.$usageArray['character_count'].' of '.$usageArray['character_limit'].' in the current billing period.'.PHP_EOL;
- 
+
 ```
 
 ### Glossary

src/DeepL.php

@@ -73,7 +73,7 @@ public function languages($type = null)
      */
     public function translate(
         $text,
-        $sourceLang = 'de',
+        $sourceLang = '',
         $targetLang = 'en',
         $tagHandling = null,
         array $ignoreTags = null,