Closes https://github.com/yuvipanda/jupyter-desktop-server/issues/25

Fix permissions on ~/.cache

Add binder-badge.yaml

https://mybinder.readthedocs.io/en/latest/howto/gh-actions-badges.html

`apt-get install xorg` somehow results in a `/home/jovyan/.cache` directory being created and owned by `root`, maybe because `HOME` is set to `/home/jovyan`? This prevents the `jovyan` user running other programs such as Firefox:

```
$ podman build -t jupyter-desktop-server .
...

$ podman run --rm jupyter-desktop-server ls -la
total 40
drwxrwxr-x. 7 jovyan users 4096 Aug 16 17:04 .
drwxr-xr-x. 3 root   root  4096 Aug 16 17:04 ..
-rw-rw-r--. 1 jovyan users  220 Feb 25 12:03 .bash_logout
-rw-rw-r--. 1 jovyan users 3770 Jun 18 03:05 .bashrc
drwx------. 2 root   root  4096 Aug 16 17:02 .cache
drwxrwxr-x. 2 jovyan users 4096 Aug 16 17:04 .conda
drwsrws---. 3 jovyan users 4096 Jun 18 03:10 .config
drwsrws---. 2 jovyan users 4096 Jun 18 03:10 .jupyter
-rw-rw-r--. 1 jovyan users  807 Feb 25 12:03 .profile
drwsrwsr-x. 2 jovyan users 4096 Jun 18 03:05 work

```

Note `fix-permissions $HOME` only makes it group writeable, it doesn't fix the owner which is why I'm using `chown` instead.
```
drwxrwxr-x. 7 jovyan users 4096 Aug 16 17:08 .
drwxr-xr-x. 3 root   root  4096 Aug 16 17:08 ..
-rw-rw-r--. 1 jovyan users  220 Feb 25 12:03 .bash_logout
-rw-rw-r--. 1 jovyan users 3770 Jun 18 03:05 .bashrc
drwxrwx---. 3 root   users 4096 Aug 16 17:08 .cache
drwxrwxr-x. 2 jovyan users 4096 Aug 16 17:08 .conda
drwsrws---. 3 jovyan users 4096 Jun 18 03:10 .config
drwsrws---. 2 jovyan users 4096 Jun 18 03:10 .jupyter
-rw-rw-r--. 1 jovyan users  807 Feb 25 12:03 .profile
drwsrwsr-x. 2 jovyan users 4096 Jun 18 03:05 work
```

Start session from $HOME

Otherwise the user will start in noVNC directory when they open a terminal
(or any other application that inherits the cwd from the session)

By default in 1.4.0, jupyter-server-proxy opens new
applications in an iframe. I don't think this should be the
default for most applications
(https://github.com/jupyterhub/jupyter-server-proxy/pull/198),
but regardless it is very nice to be explicit

Removes the server extension, so the HTML for the interface
*is* served by websockify itself. This is a fix for
https://github.com/yuvipanda/jupyter-desktop-server/issues/10
This reverts commit 18d7fb7b.

A mess of a commit, should have been several.

- Finish renaming package from jupyter_desktop to
  jupyter_desktop_server
- Revert 360f9b04. Looks like
  websockify gets super confused when you put shell in the middle
  of it and the process it is spawning.
- Add a server extension that renders a slightly modified copy
  of vnc_lite.html as /desktop. This will be modified more and more
  as we go forward. This also helps us remove the mapping present
  in the jupyter server proxy entry

- jupyter-desktop sounds like a desktop installation of
  Jupyter
- This matches the package name

We made a release!

Otherwise it'll be cwd of webroot, which is confusing as
soon as you open a terminal

Send credentials when making requests for imported modules in noVNC

A wider screen & higher resolution, to match what most current
screens are like.

We should make the default configurable, for people on low bandwidth
connections.

Not needed. This will also stop the error about not
being able to create a Desktop directory

This helps us get rid of postBuild completely, and
possibly lets us publish this as a package that can
be used elsewhere

This sucks - we are vendoring in a library *and*
modifying a single file (vnc_lite.html) in there.

Pathway out of this is to make this into a Jupyter Server
extension that can render the standalone vnc_lite.html UI
properly in the Jupyter theme.

Until then...

Helps get rid of the special VNC_APPLICATION_DIRECTORY
bit by bit

Removes need for that step in postBuild

Refactor to just be jupyter-desktop