Fix list markup: blank line required (#10591)

Judging from the other lists in this same file, it looks like a blank
line is required to separate the previous paragraph from the first list
item.

Otherwise the list is considered part of the paragraph:

- https://docs.astral.sh/ruff/settings/#lint_flake8-copyright_notice-rgx

<img width="400" alt="image"
src="https://github.com/astral-sh/ruff/assets/282592/663fa5b4-f787-4fcd-bdd6-0b891d7ad72b">

- https://docs.astral.sh/ruff/settings/#format_quote-style

<img width="400" alt="image"
src="https://github.com/astral-sh/ruff/assets/282592/809735eb-c546-4348-9311-877441bae84e">

After this change hopefully those will be rendered as proper bullet
lists.

crates/ruff_workspace/src/options.rs

@@ -1133,6 +1133,7 @@ pub struct Flake8CopyrightOptions {
     /// with the [`regex`](https://docs.rs/regex/latest/regex/) crate.
     /// Defaults to `(?i)Copyright\s+((?:\(C\)|©)\s+)?\d{4}((-|,\s)\d{4})*`, which matches
     /// the following:
+    ///
     /// - `Copyright 2023`
     /// - `Copyright (C) 2023`
     /// - `Copyright 2021-2023`
@@ -2962,6 +2963,7 @@ pub struct FormatOptions {
     pub indent_style: Option<IndentStyle>,
 
     /// Configures the preferred quote character for strings. The recommended options are
+    ///
     /// * `double` (default): Use double quotes `"`
     /// * `single`: Use single quotes `'`
     ///