You might want to add README.md on your GitHub repository
That's the standard of releasing source code on Github's release page, few example from another Bitcoin open source wallet,
https://github.com/bitcoin/bitcoin/releases/tag/v0.21.0
https://github.com/spesmilo/electrum/releases/tag/4.0.9
.zip Source Code 
Do you think BtcIO is open source?
Do you think BtcIO is open source?That's the standard of releasing source code on Github's release page, few example from another Bitcoin open source wallet,
https://github.com/bitcoin/bitcoin/releases/tag/v0.21.0
https://github.com/spesmilo/electrum/releases/tag/4.0.9