docs: Add known compatibility issue for Selenium 4.12.1 (#2008)

Author: valfirst

README.md

@@ -90,7 +90,7 @@ dependencies {
 ### Compatibility Matrix
  Appium Java Client | Selenium client
 --------------------|-----------------
- `8.5.0`, `8.5.1`   | `4.9.1`, `4.10.0`, `4.11.0`, `4.12.0`, `4.12.1`
+ `8.5.0`, `8.5.1`   | `4.9.1`, `4.10.0`, `4.11.0`, `4.12.0`, `4.12.1` (known issue: appium/java-client#2004)
  `8.4.0`            | `4.8.2`, `4.8.3`, `4.9.0`
  `8.3.0`            | `4.7.0`, `4.7.1`, `4.7.2`, `4.8.0`, `4.8.1`
  `8.2.1`            | `4.5.0`, `4.5.1`, `4.5.2`, `4.5.3`, `4.6.0`