Allow user to use multiple formatters (#14846)

Fixes #4822
- [x] Release note
- [ ] Surface formatting errors via a toast
- [x] Doc updates
- [x] Have "language-server" accept an optional name of the server.

Release Notes:

- `format` and `format_on_save` now accept an array of formatting
actions to run.
- `language_server` formatter option now accepts the name of a language
server to use (e.g. `{"language_server": {"name: "ruff"}}`); when not
specified, a primary language server is used.

---------

Co-authored-by: Thorsten <thorsten@zed.dev>

crates/project/src/prettier_support.rs

@@ -13,7 +13,7 @@ use futures::{
 };
 use gpui::{AsyncAppContext, Model, ModelContext, Task, WeakModel};
 use language::{
-    language_settings::{Formatter, LanguageSettings},
+    language_settings::{Formatter, LanguageSettings, SelectedFormatter},
     Buffer, LanguageServerName, LocalFile,
 };
 use lsp::{LanguageServer, LanguageServerId};
@@ -30,8 +30,12 @@ pub fn prettier_plugins_for_language(
     language_settings: &LanguageSettings,
 ) -> Option<&HashSet<String>> {
     match &language_settings.formatter {
-        Formatter::Prettier { .. } | Formatter::Auto => Some(&language_settings.prettier.plugins),
-        Formatter::LanguageServer | Formatter::External { .. } | Formatter::CodeActions(_) => None,
+        SelectedFormatter::Auto => Some(&language_settings.prettier.plugins),
+
+        SelectedFormatter::List(list) => list
+            .as_ref()
+            .contains(&Formatter::Prettier)
+            .then_some(&language_settings.prettier.plugins),
     }
 }