Fix link to the PHP extension (#25144)

USAMI Kenta created 

Fix broken links to [PHP
extensions](https://github.com/zed-extensions/php) from [the
documentation](https://zed.dev/docs/languages/php).

Release Notes:

- N/A

Change summary

docs/src/languages/php.md | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Detailed changes

docs/src/languages/php.md 🔗 

@@ -1,6 +1,6 @@
 # PHP
 
-PHP support is available through the [PHP extension](https://github.com/zed-industries/zed/tree/main/extensions/php).
+PHP support is available through the [PHP extension](https://github.com/zed-extensions/php).
 
 - Tree Sitter: https://github.com/tree-sitter/tree-sitter-php
 - Language Servers: