update installation method on readme

Author: eug-L

README.md

@@ -26,14 +26,16 @@ Don't have a tawk.to account yet? [Create one here.](https://www.tawk.to/?utm_so
 5. After the installation completes, click on `Enable newly added modules` to
 complete the installation.
 
-### Manual Installation
-1. Download the `tawk_to.zip` from [latest release.](https://github.com/tawk/tawk-drupal8/releases)
-2. In the extracted files, copy the `tawkto` directory to the
-`<DRUPAL_INSTALLATION>/modules` directory.
+### Composer Installation
+This method is available only if your Drupal installation has composer.
+1. Go to your `<DRUPAL_INSTALLATION>` folder (where `composer.json` lives).
+2. Run `composer require drupal/tawkto`.
 3. Log in to the your administration panel and click on `Extend`.
-4. In the module list, search for `tawk.to` and enable the module by ticking the
-checkbox beside `tawk.to Module`.
-5. Click on `Install` button to complete the installation.
+4. In the module list, click on the `Install new module` button.
+5. Click on `Choose File`, select the downloaded module, and click on the
+`Install` button.
+6. After the installation completes, click on `Enable newly added modules` to
+complete the installation.
 
 ### Configuration
 1. In your administration panel, go to `Configuration`.