chore(docs): update TOC

Author: igor-baiborodine

v4-README.md

@@ -36,7 +36,8 @@ Please use the following guidelines if you want to start a discussion:
   - [Site Initial Setup](#site-initial-setup)
   - [Theme Installation Options](#theme-installation-options)
     - [Option 1 (recommended): Adding the Theme as a Hugo Module](#option-1-recommended-adding-the-theme-as-a-hugo-module)
-    - [Option 2: Cloning/Copying the Theme Files](#option-2-cloningcopying-the-theme-files)
+    - [Option 2: Adding the Theme as a Git submodule](#option-2-adding-the-theme-as-a-git-submodule)
+    - [Option 3: Copying the Theme Files](#option-3-copying-the-theme-files)
   - [Configuration](#configuration)
   - [Webserver](#webserver)
   - [Free Hosting](#free-hosting)