docs(language_server): add readme (#7429)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

crates/oxc_language_server/README.md

@@ -0,0 +1,61 @@
+# oxc_language_server
+
+This crate provides an [LSP](https://microsoft.github.io/language-server-protocol/) Server which is used inside an editor or IDE.
+
+## Server Capabilities
+
+- [Text Document Synchronization](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_synchronization): `FULL`,
+- Workspace
+  - [Workspace Folders](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspaceFoldersServerCapabilities): `true`
+  - File Operations: `false`
+- [Code Actions Provider](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#codeActionKind):
+  - `quickfix`
+
+## Supported LSP Specifications from Server
+
+- [initialize](https://microsoft.github.io/language-server-protocol/specification#initialize)
+  - Returns the [Server Capabilities](#server-capabilities)
+- [initialized](https://microsoft.github.io/language-server-protocol/specification#initialized)
+- [shutdown](https://microsoft.github.io/language-server-protocol/specification#shutdown)
+
+### Workspace
+
+#### [workspace/didChangeConfiguration](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeConfiguration)
+
+The server expects this request when settings like `run`, `enable` or `configPath` are changed.
+The server will revalidate or reset the diagnostics for all open files and send one or more [textDocument/publishDiagnostics](#textdocumentpublishdiagnostics) requests to the client.
+
+#### [workspace/didChangeWatchedFiles](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeWatchedFiles)
+
+The server expects this request when the oxlint configuration is changed.
+The server will revalidate the diagnostics for all open files and send one or more [textDocument/publishDiagnostics](#textdocumentpublishdiagnostics) requests to the client.
+
+### TextDocument
+
+#### [textDocument/didOpen](https://microsoft.github.io/language-server-protocol/specification#textDocument_didOpen)
+
+The server will validate the file content and send a [textDocument/publishDiagnostics](#textdocumentpublishdiagnostics) request to the client.
+
+#### [textDocument/didSave](https://microsoft.github.io/language-server-protocol/specification#textDocument_didSave)
+
+When the configuration `run` is set to `onSave`, the server will validate the file content and send a [textDocument/publishDiagnostics](#textdocumentpublishdiagnostics) request to the client.
+
+#### [textDocument/didChange](https://microsoft.github.io/language-server-protocol/specification#textDocument_didChange)
+
+When the configuration `run` is set to `onType`, the server will validate the file content and send a [textDocument/publishDiagnostics](#textdocumentpublishdiagnostics) request to the client.
+
+#### [textDocument/didClose](https://microsoft.github.io/language-server-protocol/specification#textDocument_didClose)
+
+It will remove the reference internal.
+
+#### [textDocument/codeAction](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeAction)
+
+Returns a list of [CodeAction](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_codeAction)
+
+## Expected LSP Specification from Client
+
+### TextDocument
+
+#### [textDocument/publishDiagnostics](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_publishDiagnostics)
+
+Returns a [PublishDiagnostic object](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#publishDiagnosticsParams)