language: Update block_comment and documentation comment (#34861)

As suggested in https://github.com/zed-industries/zed/pull/34418, this
proposes various changes to language configs to make block comments and
doc-block-style comments more similar. In doing so, it introduces some
breaking changes into the extension schema.

This change is needed to support the changes I'm working on in #34418,
to be able to support `rewrap` in block comments like `/* really long
comment ... */`. As is, we can do this in C-style doc-block comments (eg
`/** ... */`) because of the config in `documentation`, but we can't do
this in regular block comments because we lack the info about what the
line prefix and indentation should be.

And while I was here, I did various other clean-ups, many of which feel
nice but are optional.

I would love special attention on the changes to the schema, version and
related changes; I'm totally unfamiliar with that part of Zed.

**Summary of changes**
- break: changes type of `block_comment` to same type as
`documentation_comment` (**this is the important change**)
- break: rename `documentation` to `documentation_comment` (optional,
but improves consistency w/ `line_comments` and `block_comment`)
- break/refactor?: removes some whitespace in the declaration of
`block_comment` delimiters (optional, may break things, need input; some
langs had no spaces, others did)
- refactor: change `tab_size` from `NonZeroU32` to just a `u32` (some
block comments don't seem to need/want indent past the initial
delimiter, so we need this be 0 sometimes)
- refactor: moves the `documentation_comment` declarations to appear
next to `block_comment`, rearranges the order of the fields in the TOML
for `documentation_comment`, rename backing `struct` (all optional)

**Future scope**
I believe that this will also allow us to extend regular block comments
on newline – as we do doc-block comments – but I haven't looked into
this yet. (eg, in JS try pressing enter in both of these: `/* */` and
`/** */`; the latter should extend w/ a `*` prefixed line, while the
former does not.)

Release Notes:

- BREAKING CHANGE: update extension schema version from 1 to 2, change
format of `block_comment` and rename `documentation_comment`

/cc @smitbarmase

crates/editor/src/editor_tests.rs

@@ -2875,11 +2875,11 @@ async fn test_newline_documentation_comments(cx: &mut TestAppContext) {
     let language = Arc::new(
         Language::new(
             LanguageConfig {
-                documentation: Some(language::DocumentationConfig {
+                documentation_comment: Some(language::BlockCommentConfig {
                     start: "/**".into(),
                     end: "*/".into(),
                     prefix: "* ".into(),
-                    tab_size: NonZeroU32::new(1).unwrap(),
+                    tab_size: 1,
                 }),
 
                 ..LanguageConfig::default()
@@ -3089,7 +3089,12 @@ async fn test_newline_comments_with_block_comment(cx: &mut TestAppContext) {
     let lua_language = Arc::new(Language::new(
         LanguageConfig {
             line_comments: vec!["--".into()],
-            block_comment: Some(("--[[".into(), "]]".into())),
+            block_comment: Some(language::BlockCommentConfig {
+                start: "--[[".into(),
+                prefix: "".into(),
+                end: "]]".into(),
+                tab_size: 0,
+            }),
             ..LanguageConfig::default()
         },
         None,
@@ -13806,7 +13811,12 @@ async fn test_toggle_block_comment(cx: &mut TestAppContext) {
         Language::new(
             LanguageConfig {
                 name: "HTML".into(),
-                block_comment: Some(("<!-- ".into(), " -->".into())),
+                block_comment: Some(BlockCommentConfig {
+                    start: "<!-- ".into(),
+                    prefix: "".into(),
+                    end: " -->".into(),
+                    tab_size: 0,
+                }),
                 ..Default::default()
             },
             Some(tree_sitter_html::LANGUAGE.into()),