docs: remove PostCSS plugin configuration details from RTL support documentation

docs/en/guide/i18n.md

@@ -108,4 +108,4 @@ watchEffect(() => {
 
 ## RTL Support (Experimental)
 
-For RTL support, specify `dir: 'rtl'` in config and use some RTLCSS PostCSS plugin like <https://github.com/MohammadYounes/rtlcss>, <https://github.com/vkalinichev/postcss-rtl> or <https://github.com/elchininet/postcss-rtlcss>. You'll need to configure your PostCSS plugin to use `:where([dir="ltr"])` and `:where([dir="rtl"])` as prefixes to prevent CSS specificity issues.
+For RTL support, specify `dir: 'rtl'` in config.