Add an index page with pointers to the interactive lessons

src/Documentation/sidebar.json

@@ -1,4 +1,9 @@
 [
+  {
+    "slug": "learn",
+    "label": "Learn DVC",
+    "source": "learn/index.md"
+  },
   {
     "slug": "get-started",
     "source": "get-started/index.md",

src/Nav/index.js

@@ -21,6 +21,14 @@ export default function Nav({ mobile = false }) {
         >
           Features
         </Link>
+        <Link
+          href="https://katacoda.com/dvc/courses/basics"
+          onClick={() => {
+            logEvent('menu', 'learn')
+          }}
+        >
+          Learn
+        </Link>
         <Link
           href="/doc"
           onClick={() => {

static/docs/learn/index.md

@@ -0,0 +1,22 @@
+# Learn DVC
+
+Learn basic concepts and features of DVC with these interactive lessons:
+
+1. [Data Management](https://katacoda.com/dvc/courses/basics/data) <br/> The
+   core function of DVC is data tracking and management. Let's see how to do it.
+
+2. [Getting the Best Performance](https://katacoda.com/dvc/courses/basics/performance)
+   <br/> It is important to optimize the DVC setup for having the best
+   performance with handling big data files.
+
+3. [Tracking Data Versions](https://katacoda.com/dvc/courses/basics/versioning)
+   <br/> DVC takes advantage of GIT's versioning features to keep track of the
+   data versions.
+
+4. [Sharing Data](https://katacoda.com/dvc/courses/basics/sharing) <br/> DVC
+   facilitates sharing of data between different people that work on the same
+   project.
+
+5. [Stages And Pipelines](https://katacoda.com/dvc/courses/basics/pipelines)
+   <br/> DVC has a built-in way to connect ML steps into a DAG and run the full
+   pipeline end-to-end.