Project Onboarding: Open the README

[JosephTLyons]

Currently, when you open a new project in Zed, we open the project panel to show the files, and present a blank center workspace. I think we could automatically look for README and open it. Let users see file text right away, and get into understanding the project.

• Open the README if the project has never been opened.
  • We should use the SQLite project workspace data as the source of truth of whether or not this is a first-time open of a project.
• Open the README if a project is re-opened and there are no open files.
• Open the README file in a preview tab, so it is automatically swapped out when the user chooses a new file
• We should scan for common variants of README, but only in the root-level of each project
  • README.md
  • README.txt
  • ...
• This scanning and opening should happen when doing
  • workspace: open in the command palette
  • workspace: add folder to project in the project panel
• Behavior pinned with tests
  • Assert the REAMDE is opened when:
    • Opening a never-opened project with a README
    • Opening a previously-opened project, with a README, that has no open files being recalled
  • Assert the REAMDE is not opened when:
    • Opening a project with no README (duh)
    • Opening a previously-opened project with a README
    • Opening a previously-opened project, with a README, that has open files being recalled

[pixel365]

PR #61049