feat(plugins): use @tauri-apps namespace on NPM (#368)

Co-authored-by: Amr Bashir <amr.bashir2015@gmail.com>

plugins/process/guest-js/index.ts

@@ -13,7 +13,7 @@ import { invoke } from "@tauri-apps/api/tauri";
  * Exits immediately with the given `exitCode`.
  * @example
  * ```typescript
- * import { exit } from 'tauri-plugin-process-api';
+ * import { exit } from '@tauri-apps/plugin-process';
  * await exit(1);
  * ```
  *
@@ -30,7 +30,7 @@ async function exit(code = 0): Promise<void> {
  * Exits the current instance of the app then relaunches it.
  * @example
  * ```typescript
- * import { relaunch } from 'tauri-plugin-process-api';
+ * import { relaunch } from '@tauri-apps/plugin-process';
  * await relaunch();
  * ```
  *