⚙️ Update eslint setup (#154)

Also removes `microbundle` since it kept leaving its cache dirs behind.

Author: stormwarning

.eslintrc.js

@@ -2,5 +2,9 @@ module.exports = {
     parser: '@typescript-eslint/parser',
     plugins: ['@typescript-eslint'],
     extends: ['@zazen/eslint-config'],
-    rules: {},
+    rules: {
+        // eslint doesn't think my vars are used ¯\_(ツ)_/¯
+        'no-unused-vars': 'off',
+        'prefer-const': 'off',
+    },
 }