Add eslint rule for === vs == and fix its occurence

.eslintrc.json

@@ -23,6 +23,7 @@
 	},
 	"rules": {
 		"prettier/prettier": "error",
+		"eqeqeq": "error",
 		"no-prototype-builtins": "off",
 		"no-unused-vars": "off"
 	}