Merge pull request #191 from n7space/githubactions-ci

add cmake project and github actions ci

.github/workflows/README.md

@@ -0,0 +1,41 @@
+# GitHub Actions & Workflows
+
+The `build_cmake.yml` in this directory adds a [GitHub action][1] and workflow that builds
+your plugin anytime you push commits to GitHub on Windows, Linux and macOS.
+
+The build artifacts can be downloaded from GitHub and be installed into an existing Qt Creator
+installation.
+
+When you push a tag, the workflow also creates a new release on GitHub.
+
+## Keeping it up to date
+
+Near the top of the file you find a section starting with `env:`.
+
+The value for `QT_VERSION` specifies the Qt version to use for building the plugin.
+
+The value for `QT_CREATOR_VERSION` specifies the Qt Creator version to use for building the plugin.
+
+The value for `QT_CREATOR_SNAPSHOT` can either be `NO` or `latest` or the build ID of a specific
+snapshot build for the Qt Creator version that you specified.
+
+You need to keep these values updated for different versions of your plugin, and take care
+that the Qt version and Qt Creator version you specify are compatible.
+
+## What it does
+
+The build job consists of several steps:
+
+* Install required packages on the build host
+* Download, unpack and install the binary for the Qt version
+* Download and unpack the binary for the Qt Creator version
+* Build the plugin and upload the plugin libraries to GitHub
+* If a tag is pushed, create a release on GitHub for the tag, including zipped plugin libraries
+  for download
+
+## Limitations
+
+If your plugin requires additional resources besides the plugin library, you need to adapt the
+script accordingly.
+
+[1]: https://help.github.com/en/actions/automating-your-workflow-with-github-actions/about-github-actions