### Bug description

Code available at: https://github.com/mcanouil/quarto-issues/tree/main/quarto-cli-1441

https://user-images.githubusercontent.com/8896044/179426952-4bebdf03-98a9-4fc8-b6e3-e115b4e59ab1.mov

I installed two formats via the extension mechanism (i.e., `quarto install extension umr1283/quarto-revealjs-umr1283`) which resulted in the following directory tree:

```default
.
├── _extensions
│   ├── dragonstyle
│   │   └── lexcorp
│   │       ├── _extension.yml
│   │       ├── custom.scss
│   │       ├── logo.png
│   │       └── title.png
│   └── umr1283
│       └── umr1283
│           ├── _extension.yml
│           ├── setup-ggplot2-umr1283.R
│           ├── umr1283.scss
│           └── umr1283_8199.svg
├── lexcorp.html
├── lexcorp.qmd
├── umr.html
└── umr.qmd
```

But Quarto does not like the `_extensions/umr1283/umr1283` part.

```bash
quarto preview umr.qmd --no-browser --no-watch-inputs
WARNING: More than one extension is available for umr1283 in the directory /Users/mcanouil/Projects/misc/quarto-issues/quarto-cli-14xx/_extensions.
Extensions that match:
/Users/mcanouil/Projects/misc/quarto-issues/quarto-cli-14xx/_extensions/umr1283
/Users/mcanouil/Projects/misc/quarto-issues/quarto-cli-14xx/_extensions/umr1283/umr1283
ERROR: The extension 'umr1283' is missing the expected '_extensions.yml' file.
```

Changing the organisation name directory fix the issue, i.e., `_extensions/umr1283/umr1283` to `_extensions/umr1283-whatever/umr1283`.

I wonder if some kind of "lock" file (i.e., as for `renv`or `pak`) could be created at `_extensions` root, to get information about the installed extensions (e.g., commit SHA, tag, repo, etc.).
This could also help Quarto for different extensions sources such as subdirectory (#1440).

### `quarto check` Output

```bash
[✓] Checking Quarto installation......OK
      Version: 1.0.28
      Path: /Applications/quarto/bin

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

[✓] Checking Python 3 installation....OK
      Version: 3.10.5
      Path: /opt/homebrew/opt/python@3.10/bin/python3.10
      Jupyter: (None)

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

(-) Checking R installation...........ℹ R version 4.2.1 (2022-06-23)
! Config '~/.Rprofile' was loaded!
[✓] Checking R installation...........OK
      Version: 4.2.1
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Library/Frameworks/R.framework/Versions/4.2-arm64/Resources/library
      rmarkdown: 2.14

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

### `quarto tools check` Output

```bash
[✓] Inspecting tools

Tool         Status            Installed     Latest  
chromium     Not installed     ---           869685  
tinytex      Not installed     ---           v2022.07
```
dragonstyle
2022-07-17T22:09:13Z
mcanouil
bug
v1.2
closed
[Quarto Extension]  Quarto does not like when org-name=extension-name
https://github.com/quarto-dev/quarto-cli/issues/1441