Set v4's support end date to October 2024, mention its final minor version and pa11y version; be more specific about Node support

Author: danyalaytekin

README.md

@@ -204,9 +204,9 @@ When we release a new major version we will continue to support the previous maj
 
 The following table lists the major versions available and, for each previous major version, its end-of-support date, and its final minor version released.
 
-| Major version | Final minor version | Node.js support          | Support end date |
-| :------------ | :-----------------  | :----------------------- | :--------------- |
-| `4`           |                     | `>= 12`                  | ✅ Current major version |
+| Major version | Final minor version | Node.js support              | [pa11y] version  | Support end date |
+| :------------ | :-----------------  | :--------------------------- | :--------------- | :--------------- |
+| `4`           | `4.3`               | `12`, `14`, `16`, `18`, `20` | `^6`             | October 2024     |
 | `3`           | `3.2`               | `8`, `10`                    |                  | May 2022         |
 | `2`           | `2.3`               | `4`, `6`                     |                  | January 2020     |
 | `1`           | `1.11`              | `0.10`, `0.12`, `4`, `6`     |                  | December 2016    |