The core issue here is, they are very very different.
http://modx.com/extras/package/provisioner Could try this, but you'll need to start with an older verison of MODX.. maybe 2.2 I think.
We had a script .. maybe I can post it someplace that would find / replace the database snippets calls with revo equivalents.
We've only done few backend only upgrades. 29 out of 30 times it makes sense to build anew with MODx Revo. Generally we're migrating to Bootstrap or Foundation anyway and lots of other newer methods of doing things.
ClientConfig is excellent for allowing clients to update mundane stuff you'd normally stick in a chunk and not let them have access to. Use it all the time now. Worth also mentioning VersionX by the same author (Mark H) - he runs ModMore now and they have Redactor, ContentBlocks and a really good gallery plugin too.
Both CodeMirror and Ace have their issues, but CodeMirror is probably in a better state at the moment.
I've been using pdoTools for a while now, which has (almost) drop in replacements for all the basics: Wayfinder, getResources, GoogleSitemap, Breadcrumb, getResourceField, getPage, UltimateParent. It's decent.
Hi, not sure if you still need it. But here we go :)
It's not just one single input type to fix an accordion.
First you select migx as your input type for your Template Variable. Then I think you need one "normal" as title and a rich text for the content. Finally for the front-end you could use the accordion from bootstrap.
Quickest way to set up you title and content is to create your config via the MIGX Configs.
Or you can copy paste this in to your Template Variable Form tabs:
[{ "caption" : "FAQ" "fields":[ { "field":"title", "caption":"Title" }, { "field":"content", "caption":"Content", "inputTVtype":"richtext" } ] }]
And this should go in your Grid Column:
[{ "header": "Title", "width": "160", "sortable": "true", "dataIndex": "title" }]
For your front-end you can use the GetImageList snippet:
[[!getImageList?
&tvname=__YOUR_MIGX_TV_NAME__
&tpl=__YOUR_ROW_TEMPLATE_CHUNKNAME__
]]
You can find the Bootstrap Accordion here: https://getbootstrap.com/docs/4.3/components/collapse/#accordion-example
Hope this helps a bit.