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

extensions/glsl/languages/glsl/config.toml

@@ -12,7 +12,7 @@ path_suffixes = [
     ]
 first_line_pattern = '^#version \d+'
 line_comments = ["// "]
-block_comment = ["/* ", " */"]
+block_comment = { start = "/* ", prefix = "* ", end = "*/", tab_size = 1 }
 brackets = [
     { start = "{", end = "}", close = true, newline = true },
     { start = "[", end = "]", close = true, newline = true },

extensions/html/languages/html/config.toml

@@ -2,7 +2,7 @@ name = "HTML"
 grammar = "html"
 path_suffixes = ["html", "htm", "shtml"]
 autoclose_before = ">})"
-block_comment = ["<!-- ", " -->"]
+block_comment = { start = "<!--", prefix = "", end = "-->", tab_size = 0 }
 brackets = [
     { start = "{", end = "}", close = true, newline = true },
     { start = "[", end = "]", close = true, newline = true },