Update urls

.github/CONTRIBUTING.md

@@ -1,15 +1,15 @@
 # Contributing to CKEditor
 
-We are happy to see that you would like to contribute to CKEditor! CKEditor is an Open Source product that is free for 
+We are happy to see that you would like to contribute to CKEditor! CKEditor is an Open Source product that is free for
 anyone to download, use, and customize. It has an amazing community around it that supports it in all possible ways.
 There are a few guidelines that we need contributors to follow so that the workflow is as smooth and efficient as possible.
 
-If you are preparing a pull request, see [Contributing Code and Providing Patches to CKEditor](http://docs.ckeditor.com/#!/guide/dev_contributing_code).
+If you are preparing a pull request, see [Contributing Code and Providing Patches to CKEditor](https://docs.ckeditor.com/ckeditor4/docs/#!/guide/dev_contributing_code).
 
 If you would like to contribute in any other way, you can consider the following actions:
 
-1. Create your own [plugins](http://docs.ckeditor.com/#!/guide/plugin_sdk_sample) or [skins](http://docs.ckeditor.com/#!/guide/skin_sdk_intro)
-and submit them to [CKEditor Add-Ons Repository](http://ckeditor.com/addons/plugins).
+1. Create your own [plugins](https://docs.ckeditor.com/ckeditor4/docs/#!/guide/plugin_sdk_sample) or [skins](https://docs.ckeditor.com/ckeditor4/docs/#!/guide/skin_sdk_intro)
+and submit them to [CKEditor Add-Ons Repository](https://ckeditor.com/cke4/addons/plugins/).
 2. Help localize CKEditor into your native language and update existing localizations by joining us at the
 [CKEditor UI Translation Center](https://www.transifex.com/ckeditor/ckeditor/).
 3. Join StackOverflow and share your knowledge with [fellow CKEditor users and developers](http://stackoverflow.com/questions/tagged/ckeditor).

.github/ISSUE_TEMPLATE.md

@@ -3,10 +3,10 @@
 <!--
 Replace this comment with your issue type: Bug / Feature request / Other, please explain.
 
-Please **do not report security issues here**, use the contact form at http://cksource.com/contact instead.
+Please **do not report security issues here**, use the contact form at https://ckeditor.com/contact/ instead.
 -->
 
-## [Check if the issue is already reported](http://docs.ckeditor.com/#!/guide/dev_issues_readme-section-avoid-duplicates)
+## [Check if the issue is already reported](https://docs.ckeditor.com/ckeditor4/docs/#!/guide/dev_issues_readme-section-avoid-duplicates)
 
 *Put all reference links here…*
 

.github/PULL_REQUEST_TEMPLATE.md

@@ -5,9 +5,9 @@
 ## Does your PR contain necessary tests?
 
 All patches which change the editor code must include tests. You can always read more
-on [PR testing](http://docs.ckeditor.com/#!/guide/dev_contributing_code-section-tests),
-[how to set the testing environment](http://docs.ckeditor.com/#!/guide/dev_tests) and
-[how to create tests](http://docs.ckeditor.com/#!/guide/dev_tests-section-creating-your-own-test)
+on [PR testing](https://docs.ckeditor.com/ckeditor4/docs/#!/guide/dev_contributing_code-section-tests),
+[how to set the testing environment](https://docs.ckeditor.com/ckeditor4/docs/#!/guide/dev_tests) and
+[how to create tests](https://docs.ckeditor.com/ckeditor4/docs/#!/guide/dev_tests-section-creating-your-own-test)
 in the official CKEditor documentation.
 
 ### This PR contains

.github/SUPPORT.md

@@ -4,7 +4,7 @@ If you feel you are unable to get going by yourself, you can use the following c
 
 [Stack Overflow](https://stackoverflow.com/tags/ckeditor) – a place to share problems and solutions by CKEditor developers and integrators which you can use for usage and implementation issues. CKEditor has grown as an Open Source product, thanks to the amazing community of developers and users. Use the [[ckeditor](https://stackoverflow.com/tags/ckeditor)] tag to ask a question or to help fellow developers.
 
-[GitHub Issue Tracker](https://github.com/ckeditor/ckeditor-dev/issues) – a place to report bugs, and to request new features. Before you attempt to do so, please make sure you read [the issue tracker instructions](http://docs.ckeditor.com/#!/guide/dev_issues_tracker) and thus help us optimize the management of issues. Make sure that the bug you report is not caused by a third-party software or your customizations.
+[GitHub Issue Tracker](https://github.com/ckeditor/ckeditor-dev/issues) – a place to report bugs, and to request new features. Before you attempt to do so, please make sure you read [the issue tracker instructions](https://docs.ckeditor.com/ckeditor4/docs/#!/guide/dev_issues_tracker) and thus help us optimize the management of issues. Make sure that the bug you report is not caused by a third-party software or your customizations.
 
 Please refer to the [CONTRIBUTING](https://github.com/ckeditor/ckeditor-dev/blob/master/.github/CONTRIBUTING.md) file for more information on how to support the development of CKEditor.
 
@@ -17,6 +17,6 @@ For more advanced needs (e.g. CKEditor integration in your products, or developm
 
 For more reading visit our supporting resources:
 
-* An extensive [CKEditor 4 documentation](http://docs.ckeditor.com/) with information about CKEditor features and configuration settings.
-* [CKEditor 4 samples](http://sdk.ckeditor.com/) that you can try out and even download to copy and implement in your own environment.
+* An extensive [CKEditor 4 documentation](https://docs.ckeditor.com/ckeditor4/docs/) with information about CKEditor features and configuration settings.
+* [CKEditor 4 samples](https://sdk.ckeditor.com/) that you can try out and even download to copy and implement in your own environment.
 * A knowledge base with [Frequently Asked Questions](https://support.ckeditor.com/hc/en-us/sections/115000842245-CKEditor-4-FAQ).