guide: Fix nesting of contributing pages

guide/src/SUMMARY.md

@@ -50,23 +50,23 @@
 
 --------------------------------------------------------------------------------
 
-- [Contributing](./contributing.md)
-  - [Testing](./testing.md)
-  - [Internal Design](./design.md)
-    - [JS Objects in Rust](./design/js-objects-in-rust.md)
-    - [Exporting a function to JS](./design/exporting-rust.md)
-    - [Exporting a struct to JS](./design/exporting-rust-struct.md)
-    - [Importing a function from JS](./design/importing-js.md)
-    - [Importing a class from JS](./design/importing-js-struct.md)
-    - [Rust Type conversions](./design/rust-type-conversions.md)
-    - [Types in `wasm-bindgen`](./design/describe.md)
-  - [`js-sys`](./js-sys.md)
-    - [Testing](./js-sys/testing.md)
-    - [Adding More APIs](./js-sys/adding-more-apis.md)
-  - [`web-sys`](./web-sys.md)
-    - [Overview](./web-sys/overview.md)
-    - [Testing](./web-sys/testing.md)
-    - [Logging](./web-sys/logging.md)
-    - [Supporting More Web APIs](./web-sys/supporting-more-web-apis.md)
-  - [Publishing](./publishing.md)
-  - [Team](./team.md)
+- [Contributing](./contributing/index.md)
+  - [Testing](./contributing/testing.md)
+  - [Internal Design](./contributing/design/index.md)
+    - [JS Objects in Rust](./contributing/design/js-objects-in-rust.md)
+    - [Exporting a function to JS](./contributing/design/exporting-rust.md)
+    - [Exporting a struct to JS](./contributing/design/exporting-rust-struct.md)
+    - [Importing a function from JS](./contributing/design/importing-js.md)
+    - [Importing a class from JS](./contributing/design/importing-js-struct.md)
+    - [Rust Type conversions](./contributing/design/rust-type-conversions.md)
+    - [Types in `wasm-bindgen`](./contributing/design/describe.md)
+  - [`js-sys`](./contributing/js-sys/index.md)
+    - [Testing](./contributing/js-sys/testing.md)
+    - [Adding More APIs](./contributing/js-sys/adding-more-apis.md)
+  - [`web-sys`](./contributing/web-sys/index.md)
+    - [Overview](./contributing/web-sys/overview.md)
+    - [Testing](./contributing/web-sys/testing.md)
+    - [Logging](./contributing/web-sys/logging.md)
+    - [Supporting More Web APIs](./contributing/web-sys/supporting-more-web-apis.md)
+  - [Publishing](./contributing/publishing.md)
+  - [Team](./contributing/team.md)