_includes: use zip files for macOS

We now distribute zip files for macOS instead of tarballs.

Author: bk2204

_includes/home/hero.html

@@ -9,7 +9,7 @@ <h1 class="page-heading">An open source Git extension for versioning large files
       <div class="js-download">
         <a class="button primary-cta js-os-data" data-ga-params="download,button" data-os-attr="href"
            href="https://github.com/git-lfs/git-lfs/releases/latest"
-           data-os-mac="https://github.com/git-lfs/git-lfs/releases/download/v{{site.git-lfs-release}}/git-lfs-darwin-amd64-v{{site.git-lfs-release}}.tar.gz"
+           data-os-mac="https://github.com/git-lfs/git-lfs/releases/download/v{{site.git-lfs-release}}/git-lfs-darwin-amd64-v{{site.git-lfs-release}}.zip"
            data-os-windows="https://github.com/git-lfs/git-lfs/releases/download/v{{site.git-lfs-release}}/git-lfs-windows-v{{site.git-lfs-release}}.exe">
           <span class="octicon octicon-cloud-download"></span>
           Download <span class="download-details">v{{site.git-lfs-release}}<span class="js-os-data" data-os-attr="text" data-os-mac=" (Mac)" data-os-Windows=" (Windows)"><span></span>

_includes/home/secondary.html

@@ -4,7 +4,7 @@
     <div class="column">
       <a class="dot-com-announcement js-os-data" data-os-attr="href" data-ga-params="download,banner"
          href="https://github.com/git-lfs/git-lfs/releases/latest"
-         data-os-mac="https://github.com/git-lfs/git-lfs/releases/download/v{{site.git-lfs-release}}/git-lfs-darwin-amd64-v{{site.git-lfs-release}}.tar.gz"
+         data-os-mac="https://github.com/git-lfs/git-lfs/releases/download/v{{site.git-lfs-release}}/git-lfs-darwin-amd64-v{{site.git-lfs-release}}.zip"
          data-os-windows="https://github.com/git-lfs/git-lfs/releases/download/v{{site.git-lfs-release}}/git-lfs-windows-v{{site.git-lfs-release}}.exe"
          data-os-linux="https://github.com/git-lfs/git-lfs/releases/download/v{{site.git-lfs-release}}/git-lfs-linux-amd64-v{{site.git-lfs-release}}.tar.gz">
          GitHub.com support now available. <br/><span>Install the client to get started</span>.</a>