Add new rules, fixes #10

Author: voxpelli

README.md

@@ -45,9 +45,11 @@ Then add a `.eslintrc` with the following:
 
 * :warning: [`func-style`](https://eslint.org/docs/rules/func-style) – disallows function declarations, good to be consistent with how functions are declared
 * :warning: [`no-console`](https://eslint.org/docs/rules/no-console) – warns on existence of `console.log` and similar, as they are mostly used for debugging and should not be committed
+* :stop_sign: [`no-nonoctal-decimal-escape`](https://eslint.org/docs/rules/no-nonoctal-decimal-escape) – there's no reason not to ban it
+* :stop_sign: [`no-unsafe-optional-chaining`](https://eslint.org/docs/rules/no-unsafe-optional-chaining) – enforces one to be careful with `.?` and not use it in ways that can inadvertently cause errors or `NaN` results
 * :warning: [`no-warning-comments`](https://eslint.org/docs/rules/no-warning-comments) – warns of the existence of `FIXME` comments, as they should always be fixed before pushing
 * :stop_sign: [`object-shorthand`](https://eslint.org/docs/rules/object-shorthand) – requires the use of object shorthands for properties, more tidy
-* :stop_sign: [`quote-props`](https://eslint.org/docs/rules/quote-props)– requires properties to be quoted when needed but otherwise disallows it
+* :stop_sign: [`quote-props`](https://eslint.org/docs/rules/quote-props) – requires properties to be quoted when needed but otherwise disallows it
 
 ### :package: Added ESLint rule package
 

eslintrc.json

@@ -41,6 +41,7 @@
 
     "func-style": ["warn", "expression", { "allowArrowFunctions": true }],
     "no-console": "warn",
+    "no-unsafe-optional-chaining": ["error", { "disallowArithmeticOperators": true }],
     "no-warning-comments": ["warn", { "terms": ["fixme"] }],
     "object-shorthand": ["error", "properties", { "avoidQuotes": true }],
     "quote-props": ["error", "as-needed", { "keywords": true, "numbers": true, "unnecessary": false }],