* Add prettier fixer support for typescript
* Add prettier fixer support for css and scss
* Add prettier fixer support for json
* Use getbufvar() to get &filetype
* Add support for prettier configuration file.
As of version 1.6.0, prettier allows passing a `--config` argument with
a path to a configuration file.
* Add test prettier configuration file.
* Add option to use local prettier configuration.
* Add description for new prettier option.
* Also check if the config is present before using it.