Add Next.js ESLint (#425)

* Added Next.js eslint

* added eslint to lint-staged

* Added eslint config for prettier

* Fixed eslint issues in multiple files

* Fixed error in linter

.eslintrc

@@ -0,0 +1,6 @@
+{
+  "extends": ["next", "prettier"],
+  "rules": {
+    "react/no-unescaped-entities": "off"
+  }
+}