docs: add guide for incremental build

website/docs/en/guide/optimization/build-performance.mdx

@@ -32,7 +32,7 @@ The following are methods for improving performance in development mode.
 
 Enabling lazy compilation can significantly reduce the number of modules compiled at dev startup and improve startup time.
 
-```js
+```ts title="rsbuild.config.ts"
 export default {
   dev: {
     lazyCompilation: true,
@@ -42,6 +42,24 @@ export default {
 
 > Please refer to [dev.lazyCompilation](/config/dev/lazy-compilation) for more information.
 
+### Enable incremental build
+
+Rspack provides experimental [experiments.incremental](https://rspack.dev/config/experiments#experimentsincremental) configuration, which can improve the HMR speed in development mode.
+
+```ts title="rsbuild.config.ts"
+const isDev = process.env.NODE_ENV === 'development';
+
+export default {
+  tools: {
+    rspack: {
+      experiments: {
+        incremental: isDev,
+      },
+    },
+  },
+};
+```
+
 ### Source map format
 
 In order to provide a good debugging experience, Rsbuild uses the `cheap-module-source-map` format source map by default in development mode, which is a high-quality source map format and will bring certain performance overhead.
@@ -50,7 +68,7 @@ You can improve build speed by adjusting the source map format in development mo
 
 For example to disable source map:
 
-```js
+```ts title="rsbuild.config.ts"
 export default {
   output: {
     sourceMap: {
@@ -62,7 +80,7 @@ export default {
 
 Or set the source map format of the development mode to the cheapest `eval` format:
 
-```js
+```ts title="rsbuild.config.ts"
 export default {
   output: {
     sourceMap: {

website/docs/zh/guide/optimization/build-performance.mdx

@@ -32,7 +32,7 @@ Rsbuild 默认对构建性能进行了充分优化，但是随着使用场景变
 
 启用 lazy compilation 可以显著减少开发启动时编译的模块数量，从而提升启动时间。
 
-```js
+```ts title="rsbuild.config.ts"
 export default {
   dev: {
     lazyCompilation: true,
@@ -42,6 +42,24 @@ export default {
 
 > 请参考 [dev.lazyCompilation](/config/dev/lazy-compilation) 了解更多。
 
+### 开启增量构建
+
+Rspack 提供了实验性的 [experiments.incremental](https://rspack.dev/zh/config/experiments#experimentsincremental) 配置，开启后可以提升开发阶段 HMR 的速度。
+
+```ts title="rsbuild.config.ts"
+const isDev = process.env.NODE_ENV === 'development';
+
+export default {
+  tools: {
+    rspack: {
+      experiments: {
+        incremental: isDev,
+      },
+    },
+  },
+};
+```
+
 ### Source map 格式
 
 为了提供良好的调试体验，Rsbuild 在开发模式下默认使用 `cheap-module-source-map` 格式 source map，这是一种高质量的 source map 格式，会带来一定的性能开销。
@@ -50,7 +68,7 @@ export default {
 
 比如禁用 source map：
 
-```js
+```ts title="rsbuild.config.ts"
 export default {
   output: {
     sourceMap: {
@@ -62,7 +80,7 @@ export default {
 
 或是把开发模式的 source map 格式设置为开销最小的 `eval` 格式：
 
-```js
+```ts title="rsbuild.config.ts"
 export default {
   output: {
     sourceMap: {