Feature: Configurable success notification

* Implements #217

README.md

@@ -138,6 +138,7 @@ Remove tags after OCR | These tags will be removed from the file after it has be
 OCR mode | Controls the way files are processed, which already have OCR content. For PDF files this setting corresponds to the `--skip-text`, `--redo-ocr` and `--force-ocr` parameters of `ocrmypdf`. See [official docs](https://ocrmypdf.readthedocs.io/en/latest/advanced.html#when-ocr-is-skipped) for additional information.<br>**Skip text:** skip pages completely that already contain text. Such a page will not be touched and just be copied to the final output.<br>**Redo OCR:** perform a detailed text analysis to split up pages into areas with and without text.<br>**Force OCR:** all pages will be rasterized to images and OCR will be performed on every page. |
 Keep original file version | If the switch is set, the original file (before applying OCR) will be kept. This is done by giving the file version the label `Before OC`. This version will be excluded from the automatic expiration process (see [here](https://docs.nextcloud.com/server/latest/user_manual/en/files/version_control.html#naming-a-version) for details) |
 Keep original file modification date | Restore the modification date of the original file. The original modification date will be applied to the newly created file version. This is useful if you need to preserve the file modification date, for example to be able to sort files accordingly. |	
+Send success notification | Usually the workflow would only send a notification to the user if the OCR process failed. If this option is activated, the user will also be notified if a document has been processed successfully via OCR. |
 Remove background\* | If the switch is set, the OCR processor will try to remove the background of the document before processing and instead set a white background. For PDF files this setting corresponds to the [`--remove-background`](https://ocrmypdf.readthedocs.io/en/latest/cookbook.html?highlight=remove-background#image-processing) parameter of `ocrmypdf`.<br/>:warning: Please note that this flag will currently only work with **`ocrmypdf` versions prior to 13**. It might be added in future versions again. See [here](https://github.com/ocrmypdf/OCRmyPDF/issues/884) for details. :warning:|
 Custom ocrMyPdf CLI arguments | If you want to pass custom arguments to the `ocrmypdf` CLI, you can do so here. Please note that the arguments will be passed as they are to the CLI, so make sure to use the correct syntax. Check the [official docs](https://ocrmypdf.readthedocs.io/en/latest/cookbook.html) for more information. |
 

composer.json

@@ -1,7 +1,6 @@
 {
     "require": {
-        "mikehaertl/php-shellcommand": "^1.6",
-        "cocur/chain": "^0.9.0"
+        "mikehaertl/php-shellcommand": "^1.6"
     },
     "require-dev": {
         "phpunit/phpunit": "9.3.*",