feat: add support for baseline years

README.md

@@ -56,15 +56,15 @@ export default [
 
 <!-- Rule Table Start -->
 
-| **Rule Name**                                                              | **Description**                       | **Recommended** |
-| :------------------------------------------------------------------------- | :------------------------------------ | :-------------: |
-| [`no-duplicate-imports`](./docs/rules/no-duplicate-imports.md)             | Disallow duplicate @import rules      |       yes       |
-| [`no-empty-blocks`](./docs/rules/no-empty-blocks.md)                       | Disallow empty blocks                 |       yes       |
-| [`no-invalid-at-rules`](./docs/rules/no-invalid-at-rules.md)               | Disallow invalid at-rules             |       yes       |
-| [`no-invalid-properties`](./docs/rules/no-invalid-properties.md)           | Disallow invalid properties           |       yes       |
-| [`prefer-logical-properties`](./docs//rules//prefer-logical-properties.md) | Enforce the use of logical properties |       no        |
-| [`require-baseline`](./docs/rules/require-baseline.md)                     | Enforce the use of baseline features  |       yes       |
-| [`use-layers`](./docs/rules/use-layers.md)                                 | Require use of layers                 |       no        |
+| **Rule Name**                                                            | **Description**                       | **Recommended** |
+| :----------------------------------------------------------------------- | :------------------------------------ | :-------------: |
+| [`no-duplicate-imports`](./docs/rules/no-duplicate-imports.md)           | Disallow duplicate @import rules      |       yes       |
+| [`no-empty-blocks`](./docs/rules/no-empty-blocks.md)                     | Disallow empty blocks                 |       yes       |
+| [`no-invalid-at-rules`](./docs/rules/no-invalid-at-rules.md)             | Disallow invalid at-rules             |       yes       |
+| [`no-invalid-properties`](./docs/rules/no-invalid-properties.md)         | Disallow invalid properties           |       yes       |
+| [`prefer-logical-properties`](./docs/rules/prefer-logical-properties.md) | Enforce the use of logical properties |       no        |
+| [`require-baseline`](./docs/rules/require-baseline.md)                   | Enforce the use of baseline features  |       yes       |
+| [`use-layers`](./docs/rules/use-layers.md)                               | Require use of layers                 |       no        |
 
 <!-- Rule Table End -->
 

docs/rules/require-baseline.md

@@ -87,7 +87,9 @@ h1:has(+ h2) {
 
 This rule accepts an option object with the following properties:
 
-- `available` (default: `"widely"`) - change to `"newly"` available to allow a larger number of properties and at-rules.
+- `available` (default: `"widely"`)
+    - change to `"newly"` available to allow features that have had cross-browser support for fewer than 30 months
+    - set to a numeric baseline year, for which all features that became baseline that year or earlier should be allowed (example: `2023`)
 
 ## When Not to Use It