chore: add docs

README.md

@@ -40,6 +40,11 @@ export default [
 ];
 ```
 
+## Rules
+
+- [`optimize/redundant-polyfills`](./docs/rules/redundant-polyfills.md)
+- [`optimize/avoid-micro-utilities`](./docs/rules/avoid-micro-utilities.md)
+
 ## License
 
 MIT

docs/rules/avoid-micro-utilities.md

@@ -0,0 +1,28 @@
+# Detects possibly redundant micro-utilities, preferring local/inline functionality instead
+
+This rule detects imports of "micro utilities" - very small packages which
+provide utilities you could replace with native functionality or your own
+code.
+
+## Rule Details
+
+This rule detects possibly redundant micro-utilities.
+
+The following patterns are considered warnings:
+
+```ts
+const isNaN = require('is-nan');
+isNaN(v);
+```
+
+The following patterns are not warnings:
+
+```ts
+Number.isNaN(v);
+```
+
+## When Not To Use It
+
+If you prefer the cost of pulling in many utility dependencies over
+the cost of writing the equivalent snippet yourself, it may be worth disabling
+this rule.

docs/rules/redundant-polyfills.md

@@ -0,0 +1,32 @@
+# Detects possibly redundant polyfills of natively available functionality
+
+This rule detects imports of dependencies which provide functionality now
+available natively.
+
+If your package has an `engines` constraint for `node`, it will be taken
+into account (i.e. polyfills of functionality your version doesn't yet have
+will be allowed).
+
+## Rule Details
+
+This rule detects possibly redundant polyfills.
+
+The following patterns are considered warnings:
+
+```ts
+// With no `engines` or `engines.node` is `>=7.0.0`
+const entries = require('object.entries');
+entries({foo: 'bar'});
+```
+
+The following patterns are not warnings:
+
+```ts
+// With no `engines` or `engines.node` is `>=7.0.0`
+Object.entries({foo: 'bar'});
+```
+
+## When Not To Use It
+
+If you need to support much older JS runtimes (node, browsers, etc), this
+rule may not be of much use as the polyfills are probably still useful there.