Add editorconfig-checker workflow and fix styling errors

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

.editorconfig

@@ -5,11 +5,17 @@ root = true
 
 [*]
 insert_final_newline = true
-indent_style = tab
-indent_size = 4
+indent_style = space
+indent_size = tab
+tab_width = 4
 charset = utf-8
 trim_trailing_whitespace = true
 
 [*.yml]
 indent_style = space
 indent_size = 2
+
+[*.md]
+indent_style = space
+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-20.04
+      steps:
+        - uses: actions/checkout@v3
+        - uses: editorconfig-checker/action-editorconfig-checker@main
+        - run: editorconfig-checker