created skeleton document: migration-from-5.x.md

Copied the intro and basic structure of `migration-from-4.x.md` then altered said structure to match preliminary outline discussed 2022-02-16.

migration-from-5x.md

@@ -0,0 +1,153 @@
+---
+layout: default
+title: Migrating from TinyMCE 5 to TinyMCE 6.
+title_nav: Migrating from TinyMCE 5
+description: Guidance for migrating from TinyMCE 5 to TinyMCE 6.
+keywords: migration considerations premigration pre-migration
+---
+
+<!-- A very preliminary outline and structure for the TinyMCE 5 to TinyMCE 6 migration guide. Lot’s of potentially unfounded assumptions in this but it’s something to critique at least.
+
+Perhaps the most important critique, even before we start is the following: ‘editor-core, and apis and options do overlap somewhat’. So it’s possible a different structure is better.
+
+All thoughts and suggestions on this front entirely welcome. -->
+
+Most configuration changes in TinyMCE 6 only affect complex use cases, such as customized user interface components. The process for setting up a basic TinyMCE 6 instance is the same as TinyMCE 5.
+
+This chapter describes the migration process and workarounds for customers using TinyMCE 5. It describes the settings that require updating prior to migration; and workaround procedures for deprecated, deleted, and updated features.
+
+> **Note**: For support related to migration, please contact [Tiny support](https://support.tiny.cloud/hc/en-us/requests/new). Open Source users: Please report issues on the [TinyMCE GitHub Repository](https://github.com/tinymce/tinymce/).
+
+## Contents
+
+* [Editor-Core](#editor-core)
+* [APIs](#apis)
+* [Options](#options)
+* [Plugins](#plugins)
+
+
+## Editor-Core
+
+To migrate the core TinyMCE editor to TinyMCE 6, review the following sections:
+
+* [Cloud Delivery](#clouddelivery).
+* [editor-core section 2](#editor-core-section-2).
+* [editor-core section 3](#editor-core-section-3).
+* [editor-core section 4](#editor-core-section-4).
+* [editor-core section n](#editor-core-section-n).
+
+### Cloud Delivery
+
+To use TinyMCE 6 from the {{site.cloudname}}, include this script in your HTML page. Replace ‘no-api-key’ with [your API key]({{site.accountsignup}}).
+
+```html
+<script src="{{ site.cdnurl }}" referrerpolicy="origin"></script>
+```
+
+For information on using the latest development and testing builds, see: [Cloud deployment guide - Specify editor & plugin versions]({{site.baseurl}}/cloud-deployment-guide/editor-plugin-version/).
+
+### editor-core section 2
+
+editor-core section 2 placeholder text.
+
+### editor-core section 3
+
+editor-core section 3 placeholder text.
+
+### editor-core section 4
+
+editor-core section 4 placeholder text.
+
+### editor-core section n
+
+editor-core section n placeholder text.
+
+
+
+## APIs
+
+* [APIs section 1](#apis-section-1).
+* [APIs section 2](#apis-section-2).
+* [APIs section 3](#apis-section-3).
+* [APIs section 4](#apis-section-4).
+* [APIs section n](#apis-section-n).
+
+### APIs section 1
+
+APIs section 1 placeholder text.
+
+### APIs section 2
+
+APIs section 2 placeholder text.
+
+### APIs section 3
+
+APIs section 3 placeholder text.
+
+### APIs section 4
+
+APIs section 4 placeholder text.
+
+### APIs section n
+
+APIs section n placeholder text.
+
+
+
+## Options
+
+* [Options section 1](#options-section-1).
+* [Options section 2](#options-section-2).
+* [Options section 3](#options-section-3).
+* [Options section 4](#options-section-4).
+* [Options section n](#options-section-n).
+
+### Options section 1
+
+Options section 1 placeholder text.
+
+### Options section 2
+
+Options section 2 placeholder text.
+
+### Options section 3
+
+Options section 3 placeholder text.
+
+### Options section 4
+
+Options section 4 placeholder text.
+
+### Options section n
+
+Options section n placeholder text.
+
+
+
+## Plugins
+
+* [Plugins section 1](#plugins-section-1).
+* [Plugins section 2](#plugins-section-2).
+* [Plugins section 3](#plugins-section-3).
+* [Plugins section 4](#plugins-section-4).
+* [Plugins section n](#plugins-section-n).
+
+### Plugins section 1
+
+Plugins section 1 placeholder text.
+
+### Plugins section 2
+
+Plugins section 2 placeholder text.
+
+### Plugins section 3
+
+Plugins section 3 placeholder text.
+
+### Plugins section 4
+
+Plugins section 4 placeholder text.
+
+### Plugins section n
+
+Plugins section n placeholder text.