Docs: workspace management, add latest moves to R project launching/switching guide

[jennybc]

Devs and internal R users have made recent discoveries and improvements around launching Positron in specific folders and managing multiple workspaces. I'd like to update https://positron.posit.co/rstudio-rproj-file.html (and maybe give it a new title?) with this info.

• Ctrl + R to do File: Open recent... . Can use Cmd or Opt to open in new or same window, respectively. Or can set "window.openFoldersInNewWindow": "on". Shared by @hadley.
• here's where I'll come back to write-up the move @lionel- has detailed, where the different workspaces are more like tabs in a common window

[lionel-]

In System Settings you'll have to enable tabs globally. We're working on lifting this restriction but for now this means every app that support tabs will now open new windows in tabs, including Finder, Preview, etc. Some of us actually find this more ergonomic as it simplifies Windows management at OS level.

In you Positron settings, enable native tabs:

  "window.nativeTabs": true,

You'll also need to hide the Positron toolbar:

  "window.customTitleBarVisibility": "never",

This means you'll lose direct access to some functionality like switching between layouts. This functionality is accessible via the command palette, for instance the "Customize layout" command.

You can control the text that appears in the tabs, we like to make it simpler (only the project name, not the current filename) with:

  "window.title": "${rootName}",

If you like using keyboard shortcuts, you can add bindings for workbench.action.showNextWindowTab and workbench.action.showPreviousWindowTab to navigate across project tabs.

Note that you can still have two windows side by side (useful for visual comparisons across projects or editing two projects in parallel) by dragging a tab out of the tab bar.

[juliasilge]

I'm going to remove the skeleton on this from posit-dev/positron-website#116, to be added in later in perhaps a standalone PR.

[juliasilge]

What I am removing for now:

---
title: "Workspace"
---

TO WRITE re: Workspace management

* Saving/loading tools (or lack thereof)
* Package tools
* Testing, building, etc.

Figure out how this relates to existing content re: the `.Rproj` file: [The Rproj File](rstudio-rproj-file.qmd).

Add new advice, somewhere, for opening and switching focus between workspaces with *Open Recent ...* and opening in tabs (as opposed to windows). See <https://github.com/posit-dev/positron/issues/8237>.

[juliasilge]

Let's address this dialog somewhere when talking about workspace management:

And link to the VS Code docs on "restricted mode".