Redactor docs update

Author: Mark-H

en/04_Redactor/01_v3.x/03_Usage/MIGX.md

@@ -1,11 +1,33 @@
-Redactor can be used within MIGX.
+Looking to use a rich text editor in your MIGX TV? Look no further than Redactor 3.
 
-## Standard Configuration
+## Standard configuration set
 
 [By following the MIGX Backend-Usage tutorial](https://docs.modx.com/current/en/extras/migx/migx.backend-usage), you'll get the default Redactor configuration set inside your form. This is because in the Form Tabs, you've defined `"inputTVtype": "richtext"` - which grabs the default editor in the default configuration.
 
-Do not use the "migxredactor" TV type provided by MIGX - that was for Redactor v2.
+The inputTVtype `migxredactor` (from v2, shipped with MIGX) also works.
 
-## MIGX-specific configuration
+## MIGX-specific configuration set
 
-We're investigating adding support for custom configuration sets inside MIGX.
+To use a configuration set specific to the MIGX instance, you can use the provided `migxredactor3` (note: the one with the 3 suffix!) input TV type. That accepts a `configs` option to provide the ID of the configuration set to use.
+
+In your form tabs, add two things:
+
+- `"inputTVtype": "migxredactor3"`
+- `"configs": id-of-configuration-set`
+
+For example, to use configuration set #12 on a description field, your MIGX form tabs configuration would look something like this:
+
+``` js
+[{
+    "caption": "Info",
+    "fields": [{
+        "field": "title",
+        "caption": "Title"
+    },{
+        "field": "description",
+        "caption": "Description",
+        "inputTVtype": "migxredactor3",
+        "configs": 14
+    }]
+}]
+```

en/04_Redactor/01_v3.x/Upgrades/From_2.x.md

@@ -10,11 +10,13 @@ During the first upgrade to Redactor 3, your v2 system settings will automatical
 
 This imported set will be as close as a match to your old configuration as possible, but keep in mind not every old setting has a new option. 
 
-**Your imported set is not automatically enabled.** Navigate to Extras > Redactor Configuration to find it. Open it and make sure it was properly imported and works the way you expect it to. 
+**Your imported set will be automatically enabled.** Please test it to make sure it was properly imported and works the way you expect it to.
 
-When all looks good, you can enable it from either the configuration sets grid (right click it in the list) or [the system settings](../Usage/Content).
+To help ease with upgrading when using custom CSS, the v2 "redactor-editor" class is added to your imported configuration set (in Appearance > Content style class); this will not be present on the standard configuration sets. [Learn more about custom styling in v3](../Features/Custom_CSS)
 
-**Important:** downgrading from 3 to 2 is **not supported**. If you're not sure yet if you want to start using Redactor 3 right away, start by upgrading on a development site and only upgrade production when you're happy. 
+The JSON structure for custom formatting has changed in v3 and will need to be manually updated.
+
+**Important:** downgrading from 3 to 2 is **not supported**. If you're not sure yet if you want to start using Redactor 3 right away, test the upgrade on a development site and only upgrade production when you're happy.
 
 Old system settings from v2, with a few exceptions, are removed on the first upgrade to v3.
 
@@ -29,7 +31,7 @@ While the automatic import is useful, we do recommend configuring Redactor 3 fro
 Please note this list may be incomplete
 
 - Allowed/denied tags and cleanup in general works differently now. See the Cleanup tab for details of what you can configure in v3.
-- The image float margin from v2 has changed. Previously you would set a margin for left and right floats separately, in v3 you set a single margin (in the Media tab) which will automatically be applied to the right side of the image.
+- The image float margin from v2 has changed. Previously you would set a margin for left and right floats separately, in v3 you set a single margin (in the Media tab) which will automatically be applied to the proper side of the image.
 - Source code highlighting with Ace is no longer supported. Only Codemirror is now available (enabled by default).
 - The syntax for some plugins (like Clips) has changed. In most cases these will be automatically converted by the configurator. See the configurator for details.
 - Changing the available colors for the fontcolor plugin is no longer supported.