Add editorconfig and editorconfig-checker

Signed-off-by: Christian König <ckoenig@posteo.de>

.editorconfig

@@ -0,0 +1,22 @@
+# EditorConfig is awesome: https://editorconfig.org/
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+insert_final_newline = true
+indent_style = space
+indent_size = tab
+tab_width = 4
+charset = utf-8
+trim_trailing_whitespace = true
+
+[*.yml]
+tab_width = 2
+
+[*.md]
+tab_width = 2
+
+[*.json]
+indent_size = 2

.github/workflows/editorconfig-checker.yml

@@ -0,0 +1,14 @@
+name: editorconfig-checker
+
+on:
+  pull_request:
+  push:
+
+jobs:
+  build:
+    name: editorconfig-checker
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3.2.0
+      - uses: editorconfig-checker/action-editorconfig-checker@main
+      - run: editorconfig-checker