Fix #2428. Document minimum system support.

src/blenderbim/docs/devs/system_support.rst

@@ -0,0 +1,17 @@
+System support
+==============
+
+The BlenderBIM Add-on officially supports all major 64-bit platforms, as well as
+the Python version shipped by the Blender Foundation for the most recent three
+major Blender versions:
+
+- 64-bit Linux on Python 3.10
+- 64-bit MacOS on Python 3.10
+- 64-bit MacOS M1 on Python 3.10
+- 64-bit Windows on Python 3.10
+
+Note that developer builds may exist for older versions of Python but there will
+be no guarantee of the uptime or stability of these builds.
+
+Other system specifications match the `Blender Requirements
+<https://www.blender.org/download/requirements/>`_.

src/blenderbim/docs/index.rst

@@ -30,4 +30,5 @@ The BlenderBIM Add-on lets you analyse, create, and modify OpenBIM with Blender.
    devs/running_tests
    devs/writing_docs
    devs/undo_system
+   devs/system_support
    devs/ux_guidelines