Feature request: auto-generation of `"bin"` field

[gameroman]

Clear and concise description of the problem

An option to auto-generate "bin" field, similar to how it does with "exports" field

Suggested solution

Example of how config could look

import { defineConfig } from "tsdown";

export default defineConfig({
  dts: true,

  entry: "./src/index.ts", // normal lib usage

  exports: {
    enabled: true,

    binExports: {
      tool: "./src/cli-tool.ts",
      // which would generate
      // "bin": {
      //   "tool": "./dist/cli-tool.js"
      // },
    },
  },
});

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.