Rework Object Reference Guide

Currently the document is styled as the Dyalog for Microsoft Windows Object Reference Guide; over time, objects have been added that are cross-platform. The relationships are auto-populated using a script that overwrites content, and they are not presented in a consistent way.

Both of these need work. The order in which the following tasks are done is irrelevant.

- [ ] Identify which sections in the document are cross-platform.
Once the extent of the non-Windows content has been assessed, I can make a decision on whether to split the current document into two documents (one for Windows, one cross-platform) or make the entire document cross-platform with "restrictions" at the top of pages that only apply to Windows.
- [x] Redraft each page to have sections for Purpose, Description, and Application.
Rework each page to fit these sub-headings, ensuring that the Application section includes all parents, properties, methods, events, etc (not links to pages of them such as on [this page](https://docs.dyalog.com/20.0/object-reference/objects/activexcontainer/)). Some of the redrafting might be scriptable, but each page will need to be checked manually. Remove any pages that are no longer needed (for example, pages that are currently accessed from the four links at the top of the content on the page linked above).
- [x] Create a replacement script that identifies differences for manual input.
This should identify changes between specified releases but not make any automatic changes to the document. Maybe the internal Dave I-beam could be useful for this?