Merge branch 'php-upgrade-caution' into 'master'

Put in caution about extensions potentially causing issues when upgrading PHP

See merge request !62

docs/general/requirements.md

@@ -67,6 +67,8 @@ You can find the lifecycle of current PHP versions [here](https://www.php.net/su
 
 ### PHP Version
 
+The following recommendations relate to the CiviCRM core codebase. CiviCRM native extensions, and modules and plugins that integrate CiviCRM with CMSes are maintained and released on other schedules. As they typically lag in supporting newer versions of PHP, it is recommended that you test your full site including this other software extensively as part of migrating to a newer version of PHP.
+
 | | CiviCRM 5.63 ESR | CiviCRM 5.x.x stable |
 | ---- | ---- | ---- |
 | PHP 8.2 | **not compatible.** You can support this effort [by fixing open issues](https://lab.civicrm.org/dev/core/-/issues/?sort=created_date&state=opened&label_name[]=php8%2B) or with [funding](https://civicrm.org/contribute) | **not compatible.** You can support this effort [by fixing open issues](https://lab.civicrm.org/dev/core/-/issues/?sort=created_date&state=opened&label_name[]=php8%2B) or with [funding](https://civicrm.org/contribute) |