chore: improve jsdoc of library options (#8381)

packages/vite/src/node/build.ts

@@ -203,9 +203,25 @@ export interface BuildOptions {
 }
 
 export interface LibraryOptions {
+  /**
+   * Path of library entry
+   */
   entry: string
+  /**
+   * The name of the exposed global variable. Required when the `formats` option includes
+   * `umd` or `iife`
+   */
   name?: string
+  /**
+   * Output bundle formats
+   * @default ['es', 'umd']
+   */
   formats?: LibraryFormats[]
+  /**
+   * The name of the package file output. The default file name is the name option
+   * of the project package.json. It can also be defined as a function taking the
+   * format as an argument.
+   */
   fileName?: string | ((format: ModuleFormat) => string)
 }