Improve linting

.eslintrc.json

@@ -1,6 +1,7 @@
 {
   "env": {
-    "node": true
+    "node": true,
+    "es6": true
   },
   "parserOptions": {
       "ecmaVersion": 11

.pug-lintrc.json

@@ -0,0 +1,30 @@
+{
+  "disallowAttributeInterpolation": true,
+  "disallowAttributeTemplateString": "all",
+  "disallowBlockExpansion": true,
+  "disallowClassAttributeWithStaticValue": true,
+  "disallowClassLiteralsBeforeIdLiterals": true,
+  "disallowDuplicateAttributes": true,
+  "disallowHtmlText": true,
+  "disallowIdAttributeWithStaticValue": true,
+  "disallowLegacyMixinCall": true,
+  "disallowMultipleLineBreaks": true,
+  "disallowSpacesInsideAttributeBrackets": true,
+  "disallowStringConcatenation": "aggressive",
+  "disallowTemplateString": "all",
+  "disallowTrailingSpaces": true,
+  "requireClassLiteralsBeforeAttributes": true,
+  "requireIdLiteralsBeforeAttributes": true,
+  "requireLineFeedAtFileEnd": true,
+  "requireLowerCaseAttributes": true,
+  "requireLowerCaseTags": true,
+  "requireSpaceAfterCodeOperator": true,
+  "requireStrictEqualityOperators": true,
+  "validateAttributeQuoteMarks": "'",
+  "validateAttributeSeparator": " ",
+  "validateDivTags": true,
+  "validateIndentation": 2,
+  "validateLineBreaks": "LF",
+  "validateSelfClosingTags": true,
+  "validateTemplateString": true
+}