docs: add licensing guidelines

project-docs/workflow/CODING.md

@@ -18,3 +18,4 @@ Inline comments should not explain what code from external projects is doing. Ad
 
 * [Commit guidelines](COMMITS.md)
 * [TypeScript coding guidelines](https://github.com/Microsoft/TypeScript/wiki/Coding-guidelines)
+* [Licensing guidelines](LICENSING.md)

project-docs/workflow/LICENSING.md

@@ -0,0 +1,46 @@
+# Licensing guidelines
+
+This and affiliated projects are licensed under GPLv3 or APGLv3, if not stated otherwise.
+
+## Licensing projects
+
+Copy the license from [projectmanagement](../../LICENSE) or the [official standalone](https://www.gnu.org/licenses/gpl-3.0-standalone.html) (with the filename `LICENSE`) into the root of your project.
+
+## The GPL copyright notice
+
+According to the GPLv3 guidelines for [adding the license to a new program](http://www.gnu.org/licenses/gpl-3.0-standalone.html#howto) a license note should be added at the beginning of each source file.
+
+```
+/*
+ * Copyright (C) <year> StApps
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+```
+
+### New Files
+
+The `<year>` should be inserted with the current year. E.g.:
+```
+ * Copyright (C) 2019 StApps
+```
+
+### Updating Files
+
+If the file is updated in a new year after its creation, the `<year>` should be appended as a comma seperated list with spaces in between. E.g.:
+```
+ * Copyright (C) 2018, 2019, 2021 StApps
+```
+
+## Further resources
+
+* [Coding style](CODING.md)