Just navigate to the main plugin page and then click on Download Zip.
EG: If you navigate to https://github.com/pupi1985/q2a-maximum-tag-length you'd end up downloading https://github.com/pupi1985/q2a-maximum-tag-length/archive/master.zip
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.