In order to contribute to the provider, you have to build and install it manually. Make sure you have a supported version of Go installed and working. Check out or download this repository, then open a terminal and change to its directory.
The provider must be built/installed to your plugins directory as appropriate.
Example Windows
$ go build -o C:\Users\me\AppData\Roaming\terraform.d\plugins\github.com\rymancl\dotcommonitor\1.0.0\windows_amd64/terraform-provider-dotcommonitor.exe
Example Linux
$ go build -o ~/.terraform.d/plugins/github.com/rymancl/dotcommonitor/1.0.0/darwin_amd64/terraform-provider-dotcommonitor
Any open and unassigned issues are likely up for grabs. Feel free to ping the maintainers to confirm the status of an issue or if you have any question.