Include Linux zip in list of GitHub release binaries (#3350)

* Include Linux zip in list of GitHub release binaries

This matches what has been included in recent releases.

* Fix one more Linux zip reference

* Use all 1s for the numbered list in Releasing.md

Markdown renders the numbered list correctly, and this way one can easily reorder the steps
or add new steps without needing to renumber everything.

Releasing.md

@@ -7,16 +7,17 @@ For SwiftLint contributors, follow these steps to cut a release:
     * FabricSoftenerRule
     * Top Loading
     * Fresh Out Of The Dryer
-2. Push new version: `make push_version "0.2.0: Tumble Dry"`
-3. Make sure you have the latest stable Xcode version installed and
+1. Push new version: `make push_version "0.2.0: Tumble Dry"`
+1. Make sure you have the latest stable Xcode version installed and
   `xcode-select`ed.
-4. Create the pkg installer, framework zip, and portable zip: `make release`
-5. Create a GitHub release: https://github.com/realm/SwiftLint/releases/new
+1. Create the pkg installer, framework zip, portable zip, and Linux zip:
+   `make release`
+1. Create a GitHub release: https://github.com/realm/SwiftLint/releases/new
     * Specify the tag you just pushed from the dropdown.
     * Set the release title to the new version number & release name.
     * Add the changelog section to the release description text box.
-    * Upload the pkg installer, framework zip, and portable zip you just built
+    * Upload the pkg installer, framework zip, portable zip, and Linux zip you just built
       to the GitHub release binaries.
     * Click "Publish release".
-6. Publish to Homebrew and CocoaPods trunk: `make publish`
-7. Celebrate. :tada:
+1. Publish to Homebrew and CocoaPods trunk: `make publish`
+1. Celebrate. :tada: