There are a number of ways to contribute for people all skills and skill levels.
We use the Transifex collaboration web site to translate the Shotcut user interface. Additional languages are already started but have not yet reached the 60% minimum level to be included in a Shotcut release.
An easy way for non-programmers to help is simply to participate in the Shotcut Forum by answering user’s questions. Alternatively, consider making a tutorial video on YouTube or similar.
We are now building documentation in the forum using its wiki-mode where any trusted user (some forum experience required or manual promotion) can edit the topic. Please treat this like real documentation you would see in a user manual. Some day these topics might get compiled into an offline help file or large document. Initially, we only have English, but it is a sub-category with the hope that some day a volunteer will offer to translate to another language.
You can report a bug on the Shotcut Forum using the Bug category or on GitHub Issues. Bug reports must include the Shotcut version, your operating system, and the steps. It can helpful to include a screenshot, screencast video, or project file. Please do not use this to request a feature.
After you make a filter preset that you think others would like, you can share it on the Shotcut Forum or as a GitHub Pull Request. You can locate presets on your system by choosing Settings > App Data Directory > Show… and navigating to the presets folder.
Version 19.01 added support for templates for the Overlay HTML filter. Your templates must contain one HTML file and any number of additional external files such as scripts and images. In your Shotcut install folder, look in the folder share/shotcut/qml/filters/webvfx/templates (Shotcut.app/Contents/Resources/shotcut/qml/filters/webvfx/templates on macOS).
The template Blue Middle Bar shows one way to use SVG as an image as well as one way to center text.
The engine has many additional filters that are not yet exposed. You can easily add a Shotcut UI for it. In addition, WebVfx makes it possible to add custom filters that go beyond what can be done in a HTML template including support for keyframes.
You can see existing filter UIs and add your own in your Shotcut install folder, look in the folder share/shotcut/qml/filters (Shotcut.app/Contents/Resources/shotcut/qml/filters on macOS).
The biggest impact you can make is to contribute a code change and submit that as a GitHub Pull Request. To make working on Shotcut code and some of its dependencies easier we provide some SDKs with setup instructions. Of course, you are free to try to work on the Shotcut code another way, but there is no help provided for that as it gets very complicated quickly.
All code contributions should assign copyright to Meltytech, LLC; however, exceptions may be considered for a major contribution.