chore: upgrade deps and use c8/prettier

.c8rc.json

@@ -0,0 +1,4 @@
+{
+  "reporter": ["lcov"],
+  "include": ["lib/**/*.js"]
+}

.editorconfig

@@ -1,9 +1,7 @@
-root = true
-
-[*]
-end_of_line = lf
-insert_final_newline = true
-trim_trailing_whitespace = true
-charset = utf-8
-indent_style = space
-indent_size = 4
+root = true
+
+[*]
+end_of_line = lf
+indent_size = 2
+indent_style = space
+trim_trailing_whitespace = true

.prettierrc.json

@@ -0,0 +1,10 @@
+{
+  "bracketSpacing": false,
+  "printWidth": 80,
+  "semi": true,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "trailingComma": "none",
+  "useTabs": false,
+  "arrowParens": "always"
+}

eslint.config.js

@@ -0,0 +1,10 @@
+import eslintjs from '@eslint/js';
+
+const {configs: eslintConfigs} = eslintjs;
+
+export default [
+  {
+    ...eslintConfigs.recommended,
+    files: ['lib/**/*.js'],
+  }
+];