feat: add .editorconfig and .prettierrc.js

.editorconfig

@@ -0,0 +1,15 @@
+# http://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+max_line_length = 80
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+max_line_length = 0
+trim_trailing_whitespace = false

.prettierignore

@@ -0,0 +1 @@
+*-lock.json

.prettierrc.js

@@ -0,0 +1,26 @@
+//@ts-check
+/**
+ * Prettier Configuration
+ * @type {import('prettier').Config}
+ */
+const config = {
+  overrides: [
+    // Revert JSONC parsing:
+    // https://github.com/prettier/prettier/issues/15553
+    {
+      files: ["**/*.json", "**/*.jsonc"],
+      options: {
+        parser: "json",
+      },
+    },
+    {
+      // Special rules for Markdown files
+      files: ["*.md"],
+      options: {
+        printWidth: Infinity,
+      },
+    },
+  ],
+};
+
+module.exports = config;