[AAE-6309] New process start button (#2353)

* [AEE-6309] New start process button

* [AEE-6309] Added documentation

* [AEE-6309] Change main action to object

* [AEE-6309] Clean code

* [AEE-6309] Linting fix

* [AEE-6309] Fix trashcan translation

* [AEE-6309] Fix tests

docs/extending/application-features.md

@@ -15,7 +15,7 @@ The ACA supports the following set of extension points:
 - Viewer
 - Sidebar (aka Info Drawer)
 - Content metadata presets (for `Properties` tab)
-- File list layout  
+- File list layout
 - Search
 
 All the customizations are stored in the `features` section of the configuration file:
@@ -121,6 +121,32 @@ Please refer to the [Content Actions](#content-actions) section for more details
 
 **Tip:** It is also possible to update or disable existing entries from within the external extension files. You will need to know the `id` of the target element to customize.
 
+## Main action
+
+Add possibility to show application `Main Action` button. The action is going to be shown above the `New` button, additionally `Main Action` will be highlighted as primary button, and `New` as secondary.
+
+```json
+{
+  "$schema": "../../../extension.schema.json",
+  "$version": "1.0.0",
+  "$name": "plugin1",
+
+  "features": {
+    "mainAction": {
+        "id": "plugin1.id",
+        "type": "button",
+        "title": "Create",
+        "actions": {
+          "click": "MAIN_ACTION_CALL"
+        },
+        "rules": {
+          "enabled": "app.navigation.canCall"
+        }
+      }
+  }
+}
+```
+
 ## Navigation Bar
 
 The Navigation bar consists of Link elements (`NavBarLinkRef`) organized into Groups (`NavBarGroupRef`).