How can I help NSIS?
From NSIS Wiki
There are numerous ways in which you can help NSIS develop.
First and foremost, the best way to help NSIS is by developing it. You can submit patches, create plug-ins, write functions and/or write third party applications that use or help using NSIS. You can use this Wiki to publicize your work.
Another great help would be writing documentation and/or improving the existing documentation. The more quality documentation there is, the easier it would be for new users to start using NSIS and for current users to get the best out of NSIS.