Add missing script

Docker/get_scm_version.sh

+#!/bin/bash -e
+#
+# shellcheck disable=SC1091
+#
+# Get version information from the Git repository, using the python package
+# `setuptools_scm`.
+
+# Determine top-level directory of the repository, and change directory to it.
+ROOT=$(git -C "$(dirname "${0}")" rev-parse --show-toplevel)
+cd "${ROOT}"
+
+# Check if module `setuptools_scm` is avaible.
+if ! python3 -c "import setuptools_scm" 2>/dev/null
+then
+  # Are we inside a virtual environment?
+  if [ -z "${VIRTUAL_ENV}" ]
+  then
+    # Activate virtual environment if it exists in `venv` directory,
+    # else create one first.
+    if ! [ -r "venv/bin/activate" ]
+    then
+      python3 -m venv venv
+    fi
+    . venv/bin/activate
+  fi
+  # Check again if module `setuptools_scm` is avaible, now in the virtualenv
+  # If not, install it
+  if ! python3 -c "import setuptools_scm" 2>/dev/null
+  then
+    pip install --disable-pip-version-check --quiet --require-virtualenv setuptools_scm
+  fi
+fi
+
+# Run the command to get the version information
+python3 -c "from setuptools_scm import get_version; print(get_version())"