ci(style): Add EditorConfig and relevant GH Action

.editorconfig

@@ -0,0 +1,7 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true

.github/workflows/editorconfig.yml

@@ -0,0 +1,15 @@
+name: EditorConfig Check
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    name: EditorConfig Check
+    steps:
+      - uses: actions/checkout@v2
+      - uses: editorconfig-checker/action-editorconfig-checker@v1