updated invoice documentation (#387)

var/docs/developers.md

@@ -182,57 +182,34 @@ Both follow the default naming syntax and you can link your bundle here instead
 You should NOT add them in `config/packages/kimai.yaml` but in your own bundle or the `local.yaml` [config](configurations.md), 
 otherwise they might get lost during an update.
 
-## Adding invoice renderer (FIXME)
+## Adding documents for invoice rendering 
 
-An invoice renderer is a controller action that receives an instanceof `App\Model\InvoiceModel` and returns a HTML response.
-This HTML response is the preview inside for the invoice screen. 
+In the config `kimai.invoice.documents`, you can add a list of directories with the locations of your invoice document templates ([read more](invoices.md)).
 
-Adding invoice renderer can be achieved by adding keys to the configuration `kimai.invoice.renderer` like this:
-
-```
-kimai:
-    invoice:
-        renderer:
-            default: 'App\Controller\InvoiceController::invoiceAction'
-```
-
-The name of the renderer must be unique, please prefix it with your vendor or bundle name and make sure it only contains
-character as it will be stored in a database column.
-
-## Adding invoice calculator (FIXME)
+## Adding invoice calculator
 
 An invoice calculator is a class extending `App\Invoice\CalculatorInterface` and is responsible for calculating 
-invoice rates, taxes and such.   
+invoice rates, taxes and taking care of all timesheet entries that should be displayed.   
 
-Adding invoice calculator can be achieved by adding keys to the configuration `kimai.invoice.calculator` like this:
+Every invoice calculator class will be picked up when refreshing the application cache by the [InvoiceServiceCompilerPass](https://github.com/kevinpapst/kimai2/blob/master/src/DependencyInjection/Compiler/InvoiceServiceCompilerPass.php):
 
-```
-kimai:
-    invoice:
-        calculator:
-            default: 'App\Invoice\DefaultCalculator'
-```
-
-The name of the calculator must be unique, please prefix it with your vendor or bundle name and make sure it only contains
+The ID of the calculator must be unique, please prefix it with your vendor or bundle name and make sure it only contains
 character as it will be stored in a database column.
 
-## Adding invoice-number generator (FIXME)
+Translations are stored in the `invoice-calculator.xx.xliff`.
+
+## Adding invoice-number generator
 
 An invoice-number generator is a class extending `App\Invoice\NumberGeneratorInterface` and its only task is to generate 
-a number for the invoice. In most cases you do not want to mix multiple invoice-number generators througout your invoice templates.   
+a number for the invoice. In most cases you do not want to mix multiple invoice-number generators throughout your invoices.   
 
-Adding invoice-number generator can be achieved by adding keys to the configuration `kimai.invoice.number_generator` like this:
+Every invoice number-generator class will be picked up when refreshing the application cache by the [InvoiceServiceCompilerPass](https://github.com/kevinpapst/kimai2/blob/master/src/DependencyInjection/Compiler/InvoiceServiceCompilerPass.php):
 
-```
-kimai:
-    invoice:
-        number_generator:
-            default: 'App\Invoice\DateNumberGenerator'
-```
-
-The name of the number generator must be unique, please prefix it with your vendor or bundle name and make sure it only contains
+The ID of the number generator must be unique, please prefix it with your vendor or bundle name and make sure it only contains
 character as it will be stored in a database column.
 
+Translations are stored in the `invoice-numbergenerator.xx.xliff`.
+
 ## Adding timesheet calculator
 
 A timesheet calculator will be called on stopped timesheet records. It can rewrite all values but will normally take care 

var/docs/translations.md

@@ -12,7 +12,10 @@ The files in `translations/` as a quick overview:
 - `messages` holds most of the visible application translations (like all the static UI elements and form translations)
 - `pagerfanta` includes the translations for the pagination component
 - `sidebar` holds all the translations of the right sidebar
-- `validators` only hold translations related to violations/validation of submitted form data (or API calls)
+- `validators` only holds translations related to violations/validation of submitted form data (or API calls)
+- `invoice-calculator` holds translations of calculator types (see `Adding invoice calculator` in [developers](developers.md)-section)
+- `invoice-numbergenerator` holds translations of the invoice calculator (see `Adding invoice-number generator ` in [developers](developers.md)-section)
+- `invoice-renderer` holds translations of all invoice templates ([read more](invoices.md))
 
 ## Adding a new language