[Thishis]

Originally Posted by LoRd_MuldeR

Just follow the instructions in the second link I provided. To sum it up once again:

In order to add a sub-module to your Git repository, use the command "git submodule add <submodule_url> <directory>" (for example: "git submodule add https://code.videolan.org/videolan/x264.git libs/x264").

This will add the sub-module and create a file called ".gitmodules", if it does not exist yet. You normally do not create this file manually or edit it directly.

Once the sub-module has been added, the ".gitmodules" file and the new directory can be committed just like any other file. And, as always, your changes won't appear on the remote server (e.g. Github) until you push them!

That's it

Thanks for link. I got to know to do it from the link you shared.