docs: update the links in to be absolute paths (#9)

Author: VladimirAmiorkov

README.md

@@ -98,7 +98,7 @@ The `PickerField` is a NativeScript `TextField` which means that any functionali
 The `PickerField` inherits from the `TextField` class of the `tns-core-modules/ui/text-field/text-field` module which means all of the available styling of `TextField` are available directly. Additionally the `PickerField` opens a modal window contains a `ListView` instance which inherits the css class of the `PickerField` meaning you can style that ListView elements with the use of `ListView.<your-class-name>` and simply set the `class` of the `PickerField` to `your-class-name`. The modal window also contains its own ActionBar which again inherits the css class of the `PickerField` and can be styling the same way as described above for the ListView. For full list of the available properties of which many can be styling/set via css you can refer the official API documentation of ListView [here](https://docs.nativescript.org/api-reference/modules/_ui_list_view_).
     
 ## Contribute
-We love PRs! Check out the [contributing guidelines](CONTRIBUTING.md). If you want to contribute, but you are not sure where to start - look for [issues labeled `help wanted`](https://github.com/NativeScript/nativescript-picker/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22).
+We love PRs! Check out the [contributing guidelines](https://github.com/NativeScript/nativescript-picker/blob/master/CONTRIBUTING.md). If you want to contribute, but you are not sure where to start - look for [issues labeled `help wanted`](https://github.com/NativeScript/nativescript-picker/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22).
 
 ## Get Help
-Please, use [github issues](https://github.com/NativeScript/nativescript-picker/issues) strictly for [reporting bugs](CONTRIBUTING.md#reporting-bugs) or [requesting features](CONTRIBUTING.md#requesting-new-features). For general questions and support, check out [Stack Overflow](https://stackoverflow.com/questions/tagged/nativescript) or ask our experts in [NativeScript community Slack channel](http://developer.telerik.com/wp-login.php?action=slack-invitation).
+Please, use [github issues](https://github.com/NativeScript/nativescript-picker/issues) strictly for [reporting bugs](https://github.com/NativeScript/nativescript-picker/blob/master/CONTRIBUTING.md#reporting-bugs) or [requesting features](https://github.com/NativeScript/nativescript-picker/blob/master/CONTRIBUTING.md#requesting-features). For general questions and support, check out [Stack Overflow](https://stackoverflow.com/questions/tagged/nativescript) or ask our experts in [NativeScript community Slack channel](http://developer.telerik.com/wp-login.php?action=slack-invitation).