Replace old docs with new docs repo (#24201)

docs/typescript.mdx

@@ -0,0 +1,54 @@
+---
+title: TypeScript
+description: Using TypeScript with Bun, including type definitions and compiler options
+---
+
+To install the TypeScript definitions for Bun's built-in APIs, install `@types/bun`.
+
+```zsh terminal icon="terminal"
+bun add -d @types/bun # dev dependency
+```
+
+At this point, you should be able to reference the `Bun` global in your TypeScript files without seeing errors in your editor.
+
+## Suggested `compilerOptions`
+
+Bun supports things like top-level await, JSX, and extensioned `.ts` imports, which TypeScript doesn't allow by default. Below is a set of recommended `compilerOptions` for a Bun project, so you can use these features without seeing compiler warnings from TypeScript.
+
+```json tsconfig.json icon="file-code"
+{
+  "compilerOptions": {
+    // Environment setup & latest features
+    "lib": ["ESNext"],
+    "target": "ESNext",
+    "module": "Preserve",
+    "moduleDetection": "force",
+    "jsx": "react-jsx",
+    "allowJs": true,
+
+    // Bundler mode
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "verbatimModuleSyntax": true,
+    "noEmit": true,
+
+    // Best practices
+    "strict": true,
+    "skipLibCheck": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedIndexedAccess": true,
+    "noImplicitOverride": true,
+
+    // Some stricter flags (disabled by default)
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "noPropertyAccessFromIndexSignature": false
+  }
+}
+```
+
+If you run `bun init` in a new directory, this `tsconfig.json` will be generated for you. (The stricter flags are disabled by default.)
+
+```sh terminal 	icon="terminal"
+bun init
+```