Update v7 docs to be "current version" (#1222)

* v7 docs to current version

* Update version number for 7.x

Author: wgao19

website/pages/en/versions.js

@@ -19,7 +19,7 @@
  const versionToReleaseTags = {
    '5.x': '5.0.0',
    '6.x': '6.0.0',
-   '7.x': '7.0.0-beta.0'
+   '7.x': '7.0.1'
  }
 
  function Versions() {

website/siteConfig.js

@@ -105,7 +105,7 @@ const siteConfig = {
    * After that, 7.x will no longer appear in "pre-release" versions and we should remove this line
    * More info: https://docusaurus.io/docs/en/versioning
    */
-  nextVersion: "7.x",
+  // nextVersion: "7.x",
 
   gaTrackingId : "UA-130598673-2",
 };