fix gh action

Minor cleanups and test fixes

- Added CLI option -f, --file to read template from file
- `-` will act like an alias for `-f -`

- Use `jf -` to read template from stdin
- Refactor the library, separating the CLI and template parsing logic.

NOTE: We can either pass template or pass values from stdin, but not
both.

Added CLI options.

This adds:

-r, --raw      output the raw rendered value without formatting
-p, --pretty   pretty print the output
-y, --yaml     output as YAML instead of JSON
-h, --help     print this help message
-v, --version  print the version number
--             stop parsing options

And removes:

- `%v`
- `%R`
- `%Y`
- `%J`

Also the Rust library exposes more functions, each for different
formatting options.

To allow merging arrays and objects via expansion, trailing comma after `s` and
`q` will be auto removed after the expansion if no value is passed for the
placeholder.

Example:

```bash
jf "[%(a)*s, %(b)*s]" b=2 b=1
[2,1]

jf "{%(a)**s, %(b)**s}" b=2 b=1
{"2":1}
```

- Use `%-s`, `%-q`, `%*-s`, `%*-q`, `%**-s`, `%**-q` syntax to read from stdin.
- Use `%(NAME@FILE)q` syntax to read default value from file.
- Use `%(NAME@-)q` syntax to read default value from stdin.
- Use `NAME@FILE` syntax to pass value for named placeholder from file.
- Use `NAME@-` syntax to pass value for named placeholder from stdin.
- Stdin values are separated by null (`\0`).

Examples:

```bash
seq 1 3 | xargs printf '%s\0' | jf '[%*-s]'

seq 1 3 | xargs printf '%s\0' | jf '{%q: %-s, %q: %(two)s, three: %(three@-)s}' one two two@-
```

Also, display better error for invalid expandable placeholder syntax.

Minor fix in usage test