[ADF-4152] Updated folder structure of core docs (#4415)

* [ADF-4152] Moved core library docs into subfolders

* [ADF-4152] Moved core library docs into subfolders

* [ADF-4152] Manual fixes to core doc file links

* [ADF-4152] Further automatic + manual link tidying

docs/core/services/app-config.service.md

@@ -0,0 +1,155 @@
+---
+Title: App Config service
+Added: v2.0.0
+Status: Active
+Last reviewed: 2018-09-13
+---
+
+# [App Config service](../../../lib/core/app-config/app-config.service.ts "Defined in app-config.service.ts")
+
+Supports app configuration settings, stored server side.
+
+## Class members
+
+### Methods
+
+-   **get**(key: `string`, defaultValue?: )<br/>
+    Gets the value of a named property.
+    -   _key:_ `string`  - Name of the property
+    -   _defaultValue:_   - (Optional) Value to return if the key is not found
+-   **getLocationHostname**(): `string`<br/>
+    Gets the location.hostname property.
+    -   **Returns** `string` - Value of the property
+-   **getLocationPort**(prefix: `string` = `""`): `string`<br/>
+    Gets the location.port property.
+    -   _prefix:_ `string`  - Text added before port value
+    -   **Returns** `string` - Port with prefix
+-   **getLocationProtocol**(): `string`<br/>
+    Gets the location.protocol value.
+    -   **Returns** `string` - The location.protocol string
+-   **load**(): [`Promise`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_promises)`<any>`<br/>
+    Loads the config file.
+    -   **Returns** [`Promise`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_promises)`<any>` - Notification when loading is complete
+-   **select**(property: `string`): [`Observable`](http://reactivex.io/documentation/observable.html)`<any>`<br/>
+    Requests notification of a property value when it is loaded.
+    -   _property:_ `string`  - The desired property value
+    -   **Returns** [`Observable`](http://reactivex.io/documentation/observable.html)`<any>` - Property value, when loaded
+
+## Details
+
+The [`AppConfigService`](../../core/services/app-config.service.md) service provides support for loading and accessing global application configuration settings that you store on the server side in the form of a JSON file.
+
+You may need this service when deploying your ADF-based application to production servers.
+There can be more than one server running web apps with different settings, like different addresses for Alfresco Content/Process services.
+
+You may also use the service if there is a need to change global settings for all the clients.
+
+The service is already pre-configured to look for the "app.config.json" file in the application
+root address. This allows you to deploy ADF-based web applications to multiple servers together with
+different settings files. You could use this, for example, to create separate development, staging,
+and production environments.
+
+Example of the default settings file content:
+
+**app.config.json**
+
+```json
+{
+    "ecmHost": "http://localhost:3000/ecm",
+    "bpmHost": "http://localhost:3000/bpm",
+    "application": {
+        "name": "Alfresco"
+    }
+}
+```
+
+Note that the settings in the example above are the default ones supplied with the server.
+You can override the values in your custom `app.config.json` file if necessary. 
+
+Below is a simple example of using the [`AppConfigService`](../../core/services/app-config.service.md) in practice. 
+
+**app.component.ts**
+
+```ts
+import { AppConfigService } from '@alfresco/adf-core';
+
+@Component({...})
+export class AppComponent {
+
+    constructor(appConfig: AppConfigService) {
+
+        // get nested properties by the path
+        console.log(appConfig.get('application.name'));
+
+        // use generics for type safety 
+        let version: number = appConfig.get<number>('version');
+        console.log(version);
+    }
+}
+```
+
+Your custom components can also benefit from the [`AppConfigService`](../../core/services/app-config.service.md).
+You can create an unlimited number of settings and optionally organize them as a nested JSON hierarchy.
+
+### Variable substitution in configuration strings
+
+The [`AppConfigService`](../../core/services/app-config.service.md) supports a limited set of variable substitutions to greatly simplify certain scenarios.
+
+```json
+{
+    "ecmHost": "{protocol}//{hostname}:{port}/ecm",
+    "bpmHost": "{protocol}//{hostname}:{port}/bpm",
+    "application": {
+        "name": "Alfresco"
+    }
+}
+```
+
+The supported variables are:
+
+| Variable name | Runtime value |
+| ------------- | ------------- |
+| protocol | `location.protocol` |
+| hostname | `location.hostname` |
+| port | `location.port` |
+
+## App Config onLoad Stream
+
+When the app config is loaded correctly, an `onChange` event is emitted with the whole set of app
+config properties. This comes in handy when a component needs to react to some property change or
+interact with the app config when it is finished loading:
+
+```ts
+    appConfig.onLoad.subscribe((appConfig) => {
+        console.log(appConfig); //this is the representation of the app-config
+    });
+```
+
+The `select` method lets you specify the name of a variable that should be set with the value
+of a property when the app config is loaded:
+
+```json
+    appconfig : {
+        logLevel : 'trace'
+    }
+```
+
+```ts
+    
+    appConfig.select('logLevel').subscribe((logLevelValue) => {
+        console.log(logLevelValue); //this will be 'trace';
+    });
+```
+
+## XMLHttpRequest.withCredentials
+
+In the configuration file, you can enable [XMLHttpRequest.withCredentials](https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/withCredentials)
+for @alfresco/js-api calls and PDF Viewer.
+
+```json
+{
+    "auth": {
+      "withCredentials": true
+    }
+}
+```