chore: Add build tools for translations

Signed-off-by: Wolfgang Walther <walther@technowledgy.de>

build.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# sphinx-intl fails if LC_ALL is not set
+export LC_ALL=${LC_ALL:-C}
+
+function build() {
+  sphinx-build --color -W -a -n docs -b "$@"
+}
+
+if [ $# -eq 0 ]; then
+  # clean previous build, otherwise some errors might be supressed
+  rm -rf "_build/html/default"
+
+  if [ -d languages ]; then
+    # default to updating all existing locales
+    build gettext _build/gettext
+    sphinx-intl update -p _build/gettext
+  fi
+
+  build html "_build/html/default"
+else
+  # clean previous build, otherwise some errors might be supressed
+  rm -rf "_build/html/$1"
+
+  # update and build specific locale, can be used to create new locale
+  build gettext _build/gettext
+  sphinx-intl update -p _build/gettext -l "$1"
+
+  build html "_build/html/$1" -D "language=$1"
+fi