Add docs for Ruff language server (#12344)

## Summary

This PR adds documentation for the Ruff language server.

It mainly does the following:
1. Combines various READMEs containing instructions for different editor
setup in their respective section on the online docs
2. Provide an enumerated list of server settings. Additionally, it also
provides a section for VS Code specific options.
3. Adds a "Features" section which enumerates all the current
capabilities of the native server

For (2), the settings documentation is done manually but a future
improvement (easier after `ruff-lsp` is deprecated) is to move the docs
in to Rust struct and generate the documentation from the code itself.
And, the VS Code extension specific options can be generated by diffing
against the `package.json` in `ruff-vscode` repository.

### Structure

1. Setup: This section contains the configuration for setting up the
language server for different editors
2. Features: This section contains a list of capabilities provided by
the server along with short GIF to showcase it
3. Settings: This section contains an enumerated list of settings in a
similar format to the one for the linter / formatter
4. Migrating from `ruff-lsp`

> [!NOTE]
>
> The settings page is manually written but could possibly be
auto-generated via a macro similar to `OptionsMetadata` on the
`ClientSettings` struct

resolves: #11217 

## Test Plan

Generate and open the documentation locally using:
1. `python scripts/generate_mkdocs.py`
2. `mkdocs serve -f mkdocs.insiders.yml`

scripts/generate_mkdocs.py

@@ -8,7 +8,7 @@ import re
 import shutil
 import subprocess
 from pathlib import Path
-from typing import NamedTuple
+from typing import NamedTuple, Sequence
 
 import mdformat
 import yaml
@@ -22,6 +22,8 @@ class Section(NamedTuple):
     title: str
     filename: str
     generated: bool
+    # If subsections is present, the `filename` and `generated` value is unused.
+    subsections: Sequence[Section] | None = None
 
 
 SECTIONS: list[Section] = [
@@ -30,6 +32,18 @@ SECTIONS: list[Section] = [
     Section("Installing Ruff", "installation.md", generated=False),
     Section("The Ruff Linter", "linter.md", generated=False),
     Section("The Ruff Formatter", "formatter.md", generated=False),
+    Section(
+        "Editors",
+        "",
+        generated=False,
+        subsections=[
+            Section("Editor Integration", "editors/index.md", generated=False),
+            Section("Setup", "editors/setup.md", generated=False),
+            Section("Features", "editors/features.md", generated=False),
+            Section("Settings", "editors/settings.md", generated=False),
+            Section("Migrating from ruff-lsp", "editors/migration.md", generated=False),
+        ],
+    ),
     Section("Configuring Ruff", "configuration.md", generated=False),
     Section("Preview", "preview.md", generated=False),
     Section("Rules", "rules.md", generated=True),
@@ -108,7 +122,7 @@ def main() -> None:
     Path("docs").mkdir(parents=True, exist_ok=True)
 
     # Split the README.md into sections.
-    for title, filename, generated in SECTIONS:
+    for title, filename, generated, _ in SECTIONS:
         if not generated:
             continue
 
@@ -180,7 +194,19 @@ def main() -> None:
     )
 
     # Add the nav section to mkdocs.yml.
-    config["nav"] = [{section.title: section.filename} for section in SECTIONS]
+    config["nav"] = []
+    for section in SECTIONS:
+        if section.subsections is None:
+            config["nav"].append({section.title: section.filename})
+        else:
+            config["nav"].append(
+                {
+                    section.title: [
+                        {subsection.title: subsection.filename}
+                        for subsection in section.subsections
+                    ]
+                }
+            )
 
     with Path("mkdocs.generated.yml").open("w+", encoding="utf8") as fp:
         yaml.safe_dump(config, fp)