docs: Improve issue template (#548)

Use Xdebug 3 settings and replace "Adapter" with "VS Code extension", since it makes it more understandable.

Author: zobo

ISSUE_TEMPLATE.md

@@ -1,12 +1,12 @@
 PHP version:
 Xdebug version:
-Adapter version:
+VS Code extension version:
 
 Your launch.json:
 Xdebug php.ini config:
 
-Xdebug logfile (from setting `xdebug.remote_log` in php.ini):
-Adapter logfile (from setting `"log": true` in launch.json):
+Xdebug logfile (from setting `xdebug.log` in php.ini):
+VS Code extension logfile (from setting `"log": true` in launch.json):
 
 Code snippet to reproduce: