Can't render README.qmd by default or recursively

Bug description

When running quarto render with the CLI, README.qmd files seem to be treated differently from files with other names. I have created minimal .qmd documents with nothing other than a top-level header, and the issue persists, so it is not related to the Quarto syntax of the documents. There are a few different scenarios where this occurs:

1. If I have a top-level file named README.qmd, running quarto render does not render the file. However, if I modify _quarto.yml to include

project:
   render:
      - README.qmd

then it will render just fine.

2. Even if I modify the _quarto.yml file, README.qmd files in lower-level directories are not rendered. This doesn't appear to be a globbing issue, as I've tried a few different wildcards.

Perhaps this is desired behavior, but it does not seem to be documented on the Quarto Projects page. It seems that rendering a bunch of README files in GFM for various subdirectories of a GitHub repo is a reasonable use case, so I think others may run into this issue in the future.

If this is indeed desired behavior, a simple workaround I've found is to name the Quarto file something like read_me.qmd and include output-file: README.md in the YAML header.

I am running this on MacOS Monterey 12.4.

quarto check Output

[✓] Checking Quarto installation......OK
      Version: 1.0.37
      Path: /Applications/quarto/bin

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.9.13
      Path: /usr/local/opt/python@3.9/bin/python3.9
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with python3 -m pip install jupyter

[✓] Checking R installation...........OK
      Version: 4.2.1
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Users/MJ/R_Packages_4.1
        - /Library/Frameworks/R.framework/Versions/4.2/Resources/library
      rmarkdown: 2.14

[✓] Checking Knitr engine render......OK

quarto tools check Output

[✓] Inspecting tools

Tool         Status            Installed     Latest  
chromium     Not installed     ---           869685  
tinytex      Not installed     ---           v2022.07

Checklist

• formatted your issue so it is easier for us to read?
• included a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
• documented the quarto version you're running, by pasting the output from running quarto check in the "Quarto Check Output" text area?
• documented the version of the quarto tools you're running, by providing the output from running quarto tools check in the "Quarto Tools Check Output" text area?
• documented the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
• documented which operating system you're running? If on Linux, please provide the specific distribution as well.
• upgraded to the latest version, including your versions of R, the RStudio IDE, and relevant R packages?

Start by reproducing the top-level and nested README.qmd cases with the quarto render command, including the _quarto.yml render configuration described in the report. Done means README.qmd files render by default and recursively, or the intended exclusion and supported configuration are documented.