### Bug description

Hello, 

I have a strange bug, when reading CSVs. I think that it is the fault of Quarto given the results array, which appears to end up getting interjected with html to try to set up a table?  When the file extension is changed to csv, everything works as expected. 

Code
====
```{ojs}
result = FileAttachment("path/to/csv_saved_as_txt.txt").csv()
console.dir(result)
```

Contents of file
====
```
a, b, c
1, 2, 3
4, 5, 6
```
Output
====
![image](https://user-images.githubusercontent.com/131018245/232558722-4481b78b-12d2-4ee7-bd93-d8a3867287c8.png)


Notes
=====
I am Running in VSCode on Windows 7 with Preview set to External and Render on Save

[>] Checking Quarto installation......OK
      Version: 1.2.335
      Path: C:\Users\nwilley\AppData\Local\Programs\Quarto\bin
      CodePage: 1252
[>] Checking basic markdown render....OK

[>] Checking Python 3 installation....(None)

      Unable to locate an installed version of Python 3.
      Install Python 3 from https://www.python.org/downloads/

[>] Checking R installation...........(None)

      Unable to locate an installed version of R.
      Install R from https://cloud.r-project.org/


### Checklist

- [X] Please include 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.
- [X] Please [format your issue](https://quarto.org/bug-reports.html#formatting-make-githubs-markdown-work-for-us) so it is easier for us to read the bug report.
- [X] Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [X] Please document the operating system you're running. If on Linux, please provide the specific distribution.
- [X] Please provide the output of `quarto check` so we know which version of quarto and its dependencies you're running.
jjallaire
2023-04-17T17:06:48Z
nwvhb
bug ojs-engine
v1.4
closed
CSV files read with observable are interjected with html when File Extension is txt
https://github.com/quarto-dev/quarto-cli/issues/5215