[Do not Merge] Adding release notes for 0.3 and 0.4 (#1370)

* Adding release notes for 0.3 and 0.4

website/data/docs-nav-data.json

@@ -357,6 +357,14 @@
           {
             "title": "v0.2.0",
             "path": "releases/release-notes/v0_2_0"
+          },
+          {
+            "title": "v0.3.0",
+            "path": "releases/release-notes/v0_3_0"
+          },
+          {
+            "title": "v0.4.0",
+            "path": "releases/release-notes/v0_4_0"
           }
         ]
       }