php: tweak some descriptions

pages/common/php.md

@@ -2,11 +2,11 @@
 
 > PHP command line interface.
 
-- Parse and execute a file:
+- Parse and execute a php script:
 
 `php {{file}}`
 
-- Check syntax (lint):
+- Check syntax on (i.e. lint) a PHP script:
 
 `php -l {{file}}`
 
@@ -14,7 +14,7 @@
 
 `php -a`
 
-- Run PHP code. Notes: a) Don't use <? ?> tags; b) Escape double quotes with backslash:
+- Run PHP code (Notes: Don't use <? ?> tags; escape double quotes with backslash):
 
 `php -r "{{code}}"`