Add dev script for @gitbook/expr (#3700)

.changeset/blue-countries-beg.md

@@ -0,0 +1,5 @@
+---
+"@gitbook/expr": patch
+---
+
+Add dev script for @gitbook/expr

package.json

@@ -16,7 +16,7 @@
     },
     "private": true,
     "scripts": {
-        "dev": "turbo run dev",
+        "dev": "turbo run dev --concurrency 20",
         "build": "turbo run build",
         "clean-deps": "rm -rf node_modules && rm -rf packages/*/node_modules",
         "typecheck": "turbo run typecheck",

packages/expr/package.json

@@ -31,7 +31,8 @@
         "build": "tsdown --project tsconfig.build.json",
         "typecheck": "tsc --noEmit",
         "unit": "bun test",
-        "clean": "rm -rf ./dist"
+        "clean": "rm -rf ./dist",
+        "dev": "bun run build -- --watch"
     },
     "files": ["dist", "README.md", "CHANGELOG.md"]
 }