docs: set up client-side redirects from previous era docs urls (#10921)

* one simple redirect, as a test

* adding license to header

* painstakingly added SEO redirects!

* addressed feedback and ran lint-fix!

* lets try newline again!

* Revert "lets try newline again!"

This reverts commit 20f89bd23c.

* Revert "Revert "lets try newline again!""

This reverts commit e441edc54a.

* wait... there were TWO newlines?

Co-authored-by: Evan Rusackas <evan@preset.io>

docs/src/pages/docs/contributing-page.mdx

@@ -11,7 +11,7 @@ Superset is currently being incubated at
 contributors (or committers) to Superset communicate primarily in the following channels (all of
 which you can join):
 
-- [mailing list](https://lists.apache.org/list.html?dev@superset.apache.org)
+- [Mailing list](https://lists.apache.org/list.html?dev@superset.apache.org)
 - [Apache Superset Slack community](https://apache-superset.slack.com/join/shared_invite/zt-g8lpruog-HeqpgYrwdfrD5OYhlU7hPQ#/)
 - [Github issues and PR's](https://github.com/apache/incubator-superset/issues)
 

docs/src/pages/index.tsx

@@ -450,7 +450,9 @@ const Theme = () => {
 
             <ul className="databaseList">
               {Databases.map(
-                ({ title, href, imgName: imageName, width, height }) => (
+                ({
+                  title, href, imgName: imageName, width, height,
+                }) => (
                   <a
                     href={href}
                     target="_blank"
@@ -472,11 +474,14 @@ const Theme = () => {
             </ul>
             <span className="databaseSub">
               {' '}
-              ... and any other SQLAlchemy{' '}
+              ... and any other SQLAlchemy
+              {' '}
               <a href="https://superset.incubator.apache.org/installation.html#database-dependencies">
                 {' '}
-                compatible databases{' '}
-              </a>{' '}
+                compatible databases
+                {' '}
+              </a>
+              {' '}
             </span>
           </div>
         </div>