Autodetect parser name with prettier by default (#11558)

Closes https://github.com/zed-industries/zed/issues/11517 

* Removes forced prettier parser name for languages, making `auto`
command to run prettier on every file by default.
* Moves prettier configs away from plugin language declarations into
language settings

Release Notes:

- N/A

crates/languages/src/json/config.toml

@@ -8,5 +8,4 @@ brackets = [
     { start = "[", end = "]", close = true, newline = true },
     { start = "\"", end = "\"", close = true, newline = false, not_in = ["string"] },
 ]
-prettier_parser_name = "json"
 tab_size = 2