Support for custom php.ini for the built-in PHP web server.

Support for custom php.ini for the built-in PHP web server.

A new CONFIG attribute, which defaults to 'php-ts-mode-php-config',
allows an alternative php.ini file to be specified for the built-in web
server.  The 'php-ts-mode-run-php-webserver' function, when called
interactively with a prefix argument, also requires this new attribute.
* lisp/progmodes/php-ts-mode.el (php-ts-mode--parent-html-bol):
Fix docstring.
* lisp/progmodes/php-ts-mode.el (php-ts-mode-run-php-webserver):
New CONFIG attribute.  Update docstring.
* lisp/progmodes/php-ts-mode.el (php-ts-mode--webserver-read-args):
Support the new TYPE.  Update docstring.  (Bug#72966)

(cherry picked from commit bb239841670f9bf87576c8196c41fdf295d5eac2)