_content: download link on install doc goes to download page

There is no way to reliably detect system architecture and the
install doc page is missing appropriate legal disclaimers and
notifications. Updating the button to redirect to the download
page.

For #golang/go#52487.

Change-Id: I032ac3ea3699a89acc916a8ffeafc018d51ff8f3
Reviewed-on: https://go-review.googlesource.com/c/website/+/480955
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
Auto-Submit: Jamal Carvalho <jamal@golang.org>
diff --git a/_content/doc/download.js b/_content/doc/download.js
index 324545d..ef9efb4 100644
--- a/_content/doc/download.js
+++ b/_content/doc/download.js
@@ -20,18 +20,8 @@
         const files = data[0]['files'];
         for (var i = 0; i < files.length; i++) {
           let file = files[i].filename;
-          let fileSize = files[i].size;
           if (file.match('.linux-amd64.tar.gz$')) {
             this.linuxFileName = file;
-            this.linuxFileSize = Math.round(fileSize / Math.pow(1024, 2));
-          }
-          if (file.match('.darwin-amd64(-osx10.8)?.pkg$')) {
-            this.macFileName = file;
-            this.macFileSize = Math.round(fileSize / Math.pow(1024, 2));
-          }
-          if (file.match('.windows-amd64.msi$')) {
-            this.windowsFileName = file;
-            this.windowsFileSize = Math.round(fileSize / Math.pow(1024, 2));
           }
         }
         this.detectOS();
@@ -39,7 +29,7 @@
         if (osTab !== null) {
           osTab.click();
         }
-        this.setDownloadForOS(this.osName);
+        this.setVersion(data[0].version);
       })
       .catch(console.error);
       this.setEventListeners();
@@ -51,32 +41,10 @@
     });
   }
 
-  // Set the download button UI for a specific OS.
-  setDownloadForOS(osName) {
-    const baseURL = '/dl/';
-
-    switch(osName){
-      case 'linux':
-        document.querySelector('.js-downloadDescription').textContent =
-          'Download (' + this.parseVersionNumber(this.linuxFileName) + ')';
-        document.querySelector('.js-download').href = baseURL + this.linuxFileName;
-        break;
-      case 'mac':
-        document.querySelector('.js-downloadDescription').textContent =
-          'Download (' + this.parseVersionNumber(this.macFileName) + ')';
-        document.querySelector('.js-download').href = baseURL + this.macFileName;
-        break;
-      case 'windows':
-        document.querySelector('.js-downloadDescription').textContent =
-          'Download (' + this.parseVersionNumber(this.windowsFileName) + ')';
-        document.querySelector('.js-download').href = baseURL + this.windowsFileName;
-        break;
-      default:
-        document.querySelector('.js-downloadDescription').textContent =
-          'Visit the downloads page.';
-        document.querySelector('.js-download').href = baseURL;
-        break;
-    }
+  // Set the download button UI version.
+  setVersion(latest) {
+    document.querySelector('.js-downloadDescription').textContent =
+      `Download (${this.parseVersionNumber(latest)})`;
   }
 
   // Updates install tab with dynamic data.
@@ -125,7 +93,6 @@
   handleTabClick(e) {
     const el = (e.target);
     this.activateTab(Array.prototype.indexOf.call(this.tabs, el));
-    this.setDownloadForOS(el.id);
     this.setInstallTabData(el.id);
   }
 
diff --git a/_content/doc/install.html b/_content/doc/install.html
index bc4e829..4930583 100644
--- a/_content/doc/install.html
+++ b/_content/doc/install.html
@@ -20,8 +20,10 @@
   </li>
 </ul>
 <p class="DownloadBtn">
-  <a href="/dl/" id="start" class="btn download js-download">
-    <span id="download-description" class="js-downloadDescription"></span>
+  <a href="/dl/" id="start" class="btn download">
+    <span id="download-description" class="js-downloadDescription">
+      Download
+    </span>
   </a>
 </p>
 <p>