Adding more detail to the Split Views page in the User Manuals

[churuzzz]

With the addition of the new features, I think the docs should be updated to reflect the new shortcut as well as list all the different methods that currently exist for initiating Split Views in the browser (ie: drag-n-drop, multi-select, ...). The shortcuts are available at the bottom of the page but I think they should be key to the learning experience for using splits to the most of their capabilities and therefor included as "Creating a Split View" methods.

At the bottom, instead, I believe the customizable preferences should be listed or at the very least a link to the appropriate section of the "Hidden Preferences" page.

(edit) Adding to this:

Referring to the shortcuts as "Toggles" misrepresents how they function. Once you've opened a split view, using any of othe shortcuts for starting a split view don't do anything. You'd have to select more tabs as well as the existing split itself or end the split and start a new one.

[churuzzz]

I've started working on a PR for these changes but wanted to open discussion about this change.