yes, there is.

according to this gist, by cobyism, you can use subtrees (not to be confused with the subtree merge strategy):

git subtree push --prefix <your-path> origin gh-pages 

from the git-subtree docs on git's source code:

Subtrees allow subprojects to be included within a subdirectory of the main project, optionally including the subproject's entire history.

For example, you could include the source code for a library as a subdirectory of your application.

according to this gist, by cobyism, you can use subtrees (not to be confused with the subtree merge strategy):

git subtree push --prefix <your-path> origin gh-pages 

from the git-subtree docs on git's source code:

Subtrees allow subprojects to be included within a subdirectory of the main project, optionally including the subproject's entire history.

For example, you could include the source code for a library as a subdirectory of your application.