docs: clarify what to do with unofficial casks

doc/development/adding_a_cask.md

@@ -201,7 +201,7 @@ Forks should have the vendor’s name as a prefix on the Cask’s file name and
 
 ### Unofficial, Vendorless, and Walled Builds
 
-Please submit these to [caskroom/homebrew-unofficial](http://github.com/caskroom/homebrew-unofficial). If you’ve made an unofficial build and need a place to host it, contact our sister project [alehouse](https://github.com/alehouse).
+We do not accept these casks since they offer a higher-than-normal security risk. [alehouse/homebrew-unofficial](https://github.com/alehouse/homebrew-unofficial) is a sister repo where you may wish to submit your cask.
 
 ### Fonts
 

doc/faq/rejected-casks.md

@@ -11,8 +11,8 @@ Common reasons to reject a Cask entirely:
   + Similarly, the app already exists in Homebrew, and the Homebrew-Cask version wouldn’t add anything to it.
 + The app has been rejected before due to an issue we cannot fix, and this new submission doesn’t fix that . An example would be [the first submission of `soapui`](https://github.com/caskroom/homebrew-cask/pull/4939), whose installation problems were not fixed in the two subsequent submissions ([#9969](https://github.com/caskroom/homebrew-cask/pull/9969), [#10606](https://github.com/caskroom/homebrew-cask/pull/10606)).
 + The Cask is a duplicate. These submissions mostly occur when the [token reference](../cask_language_reference/token_reference.md) was not followed.
++ The download URL for the app is both behind a login/registration form and from a host that differs from the homepage, meaning users can’t easily verify its authenticity. [alehouse/homebrew-unofficial](https://github.com/alehouse/homebrew-unofficial) is a sister repo where you may wish to submit your cask.
 
 Common reasons to reject a Cask from the main repo:
 
 + The app is an alternate edition or a legacy or development version of a Cask already in the main repo, and as such should be submitted to [caskroom/versions](https://github.com/caskroom/homebrew-versions) ([documented](../development/adding_a_cask.md#beta-unstable-development-nightly-legacy-or-alternative-versions)). Common offenders include [Sublime Text 3](https://github.com/caskroom/homebrew-cask/search?utf8=%E2%9C%93&q=sublime+text+3&type=Issues) and [Firefox Developer Edition](https://github.com/caskroom/homebrew-cask/search?q=firefox+developer+edition&type=Issues&utf8=%E2%9C%93).
-+ The download URL for the app is both behind a login/registration form and is from a host that differs from the homepage, meaning users can’t easily verify its authenticity, and as such should be submitted to [caskroom/unofficial](https://github.com/caskroom/homebrew-unofficial) ([documented](../development/adding_a_cask.md#unofficial-vendorless-and-walled-builds)).