refactor: improve setup of type declaration files (#5914)

packages/docusaurus-plugin-debug/src/plugin-debug.d.ts

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/// <reference types="@docusaurus/module-type-aliases" />
+
+declare module '@theme/DebugConfig' {
+  export default function DebugMetadata(): JSX.Element;
+}
+
+declare module '@theme/DebugContent' {
+  import type {AllContent} from '@docusaurus/types';
+
+  export interface Props {
+    readonly allContent: AllContent;
+  }
+  export default function DebugContent(props: Props): JSX.Element;
+}
+
+declare module '@theme/DebugGlobalData' {
+  export default function DebugGlobalData(): JSX.Element;
+}
+
+declare module '@theme/DebugJsonView' {
+  export interface Props {
+    readonly src: unknown;
+    readonly collapseDepth?: number;
+  }
+  export default function DebugJsonView(props: Props): JSX.Element;
+}
+
+declare module '@theme/DebugLayout' {
+  export default function DebugLayout(props: {
+    children: ReactNode;
+  }): JSX.Element;
+}
+
+declare module '@theme/DebugRegistry' {
+  export default function DebugRegistry(): JSX.Element;
+}
+
+declare module '@theme/DebugRoutes' {
+  export default function DebugRoutes(): JSX.Element;
+}
+
+declare module '@theme/DebugSiteMetadata' {
+  export default function DebugSiteMetadata(): JSX.Element;
+}