When formatting command is defined with symbol `inplace`, it doesn't
work.
I'm using [casey/just](https://github.com/casey/just) (v1.5.0).
It doesn't support formatting of `stdin`, but it supports in-place
formatting with command `just --unstable --fmt --justfile
/tmp/justfile`. So I've added a list to to `apheleia-formatters` custom
variable:
```elisp
(add-to-list 'apheleia-formatters
'(just . ("just" "--unstable" "--fmt" "--justfile" inplace))
"APPEND:non-nil")
```
Minimal `justfile` before formatting (there is one space before `echo`):
```make
rule:
echo test
```
Expected formatting result (there are four spaces before `echo`):
```make
rule:
echo test
```
Without this pull request there are no visible changes after
<kbd>C-u</kbd> <kbd>M-x</kbd> `apheleia-format-buffer` <kbd>RET</kbd>
`just` <kbd>RET</kbd>. When this pull request is applied, formatting
proceed as expected.
Co-authored-by: Radon Rosborough <radon@intuitiveexplanations.com>