[improve-docs] Remove packagist update schedule article

It is wrong and doesn't belong in the composer docs.

doc/articles/packagist-update-schedule.md

@@ -1,25 +0,0 @@
-# Packagist Update Schedule
-
-## How often does Packagist crawl newly added packages?
-
-New packages will be crawled **within ten minutes**.
-
-
-## How often does Packagist crawl existing packages?
-
-Existing packages will be crawled **every hour**.
-
-
-## How often does the Packagist search index update?
-
-The search index is updated **every five minutes**. It will index (or reindex)
-any package that has been crawled since the last time the search
-indexer ran.
-
-
-## Can Packagist be triggered to recrawl a package (on commit or by other means)?
-
-Yes, you can click the "Force update" button on your package page if you are
-logged in as a maintainer. The recommended way is to set up the GitHub hook,
-you can find the URL and instructions on your Packagist
-[profile](http://packagist.org/profile/) page.