[nandan-varma]

Motivation

Closes #970. Editor validation and autocomplete for the config file.

Modifications

• Public/openapi-generator-config.schema.json: all keys, enums and the nested filter/typeOverrides objects; $id is the raw URL.
• Test_ConfigJSONSchema: checks keys against CodingKeys, nested keys, enum values, and that a sample config built from the schema decodes as _UserConfig.
• Docs: "Editor support" section in Configuring the generator.
• Example and tutorial configs: added the # yaml-language-server: $schema=… line.
• .licenseignore: added Public/*, since JSON can't carry the license header.

Result

Editors with the YAML language server validate and autocomplete the config. Adding a key or enum case without updating the schema fails CI.

Test Plan

• New unit test and full swift test pass.
• Manual check in VS Code: a typo'd key and a bad enum value are flagged.

Notes for reviewers:

• Nested objects are stricter than the parser on purpose.
• accessModifier allows fileprivate/private; the docs list only public, package and internal.
• Nested keys rely on synthesized Codable.

[czechboy0]

Thanks @nandan-varma - I added a few more tweaks, looks great overall