Update welcome notebook

Author: lukasmasuch

resources/tutorials/welcome.ipynb

@@ -20,9 +20,9 @@
     "<br>\n",
     "<div align=\"center\"><div style=\"display: inline-flex;\">\n",
     "    <a href=\"https://hub.docker.com/r/mltooling/ml-workspace\" title=\"Docker Pulls\"><img  src=\"https://img.shields.io/docker/pulls/mltooling/ml-workspace.svg\"></a>\n",
-    "    <a href=\"https://hub.docker.com/r/mltooling/ml-workspace\" title=\"Docker Image Metadata\"><img style=\"margin-left: 5px;\" src=\"https://images.microbadger.com/badges/image/mltooling/ml-workspace.svg\"></a>\n",
-    "     <a href=\"https://github.com/ml-tooling/ml-workspace/issues\" title=\"Open Issues\"><img style=\"margin-left: 5px;\"  src=\"https://img.shields.io/github/issues/ml-tooling/ml-workspace\"></a>\n",
+    "    <a href=\"https://github.com/ml-tooling/ml-workspace/issues\" title=\"Open Issues\"><img style=\"margin-left: 5px;\"  src=\"https://img.shields.io/github/issues/ml-tooling/ml-workspace\"></a>\n",
     "    <a href=\"https://gitter.im/ml-tooling/ml-workspace\" title=\"Chat on Gitter\"><img style=\"margin-left: 5px;\" src=\"https://badges.gitter.im/ml-tooling/ml-workspace.svg\"></a>\n",
+    "    <a href=\"https://mltooling.substack.com/subscribe\" title=\"Subscribe to newsletter\"><img style=\"margin-left: 5px;\"  src=\"http://bit.ly/3bpQ1Av\"></a>\n",
     "    <a href=\"https://github.com/ml-tooling/ml-workspace\" title=\"ML Workspace Github Stars\"><img style=\"margin-left: 5px;\" src=\"https://img.shields.io/github/stars/ml-tooling/ml-workspace?style=social\"></a>\n",
     "    <a href=\"https://twitter.com/mltooling\" title=\"ML Tooling on Twitter\"><img style=\"margin-left: 5px;\" src=\"https://img.shields.io/twitter/follow/mltooling.svg?style=social\"></a>\n",
     "</div></div>\n",
@@ -85,7 +85,7 @@
     "\n",
     "The workspace is equipped with a selection of best-in-class open-source development tools to help with the machine learning workflow. Many of these tools can be started from the `Open Tool` menu from Jupyter (the main application of the workspace):\n",
     "\n",
-    "<img style=\"width: 100%\" src=\"https://github.com/ml-tooling/ml-workspace/raw/master/docs/images/features/open-tools.png\"/>\n",
+    "<img style=\"width: 100%\" src=\"https://github.com/ml-tooling/ml-workspace/raw/main/docs/images/features/open-tools.png\"/>\n",
     "\n",
     "### Install Anything\n",
     "\n",
@@ -790,11 +790,12 @@
     "    </tr>\n",
     "    <tr>\n",
     "        <td style=\"text-align: left;\">👩‍💻 Usage Questions</td>\n",
-    "        <td style=\"text-align: left;\"><a href=\"https://stackoverflow.com/questions/tagged/ml-tooling\" title=\"Open Question on Stackoverflow\"><img align=\"left\" src=\"https://img.shields.io/badge/stackoverflow-ml--tooling-orange.svg\"></a> <a href=\"https://gitter.im/ml-tooling/ml-workspace\" title=\"Chat on Gitter\"><img align=\"left\" style=\"margin-left: 5px;\" src=\"https://badges.gitter.im/ml-tooling/ml-workspace.svg\"></a></td>\n",
+    "        <td style=\"text-align: left;\"><a href=\"https://github.com/ml-tooling/ml-workspace/issues?q=is%3Aopen+is%3Aissue+label%3Asupport+sort%3Areactions-%2B1-desc\" title=\"Open Support Request\"> <img align=\"left\" src=\"https://img.shields.io/github/issues/ml-tooling/ml-workspace/support.svg?label=support%20request\"></a> <a href=\"https://stackoverflow.com/questions/tagged/ml-tooling\" title=\"Open Question on Stackoverflow\"><img align=\"left\" style=\"margin-left: 5px;\" src=\"https://img.shields.io/badge/stackoverflow-ml--tooling-orange.svg\"></a> <a href=\"https://gitter.im/ml-tooling/ml-workspace\" title=\"Chat on Gitter\"><img align=\"left\" style=\"margin-left: 5px;\" src=\"https://badges.gitter.im/ml-tooling/ml-workspace.svg\"></a></td>\n",
     "    </tr>\n",
     "    <tr>\n",
-    "        <td style=\"text-align: left;\">🗯 General Discussion</td>\n",
-    "        <td style=\"text-align: left;\"><div align=\"left\"><a href=\"https://gitter.im/ml-tooling/ml-workspace\" title=\"Chat on Gitter\"><img align=\"left\" src=\"https://badges.gitter.im/ml-tooling/ml-workspace.svg\"></a><a href=\"https://twitter.com/mltooling\" title=\"ML Tooling on Twitter\"><img align=\"left\" style=\"margin-left: 5px;\" src=\"https://img.shields.io/twitter/follow/mltooling.svg?style=social\"></a></div></td>\n",
+    "        <td style=\"text-align: left;\">📢 Announcements</td>\n",
+    "        <td style=\"text-align: left;\">\n",
+    "            <div align=\"left\"><a href=\"https://gitter.im/ml-tooling/ml-workspace\" title=\"Chat on Gitter\"><img  align=\"left\"  src=\"https://badges.gitter.im/ml-tooling/ml-workspace.svg\"></a> <a href=\"https://mltooling.substack.com/subscribe\" title=\"Subscribe for updates\"><img style=\"margin-left: 5px;\" align=\"left\"  src=\"http://bit.ly/2Md9rxM\"></a> <a href=\"https://twitter.com/mltooling\" title=\"ML Tooling on Twitter\"><img style=\"margin-left: 5px;\" align=\"left\"  src=\"https://img.shields.io/twitter/follow/mltooling.svg?style=social&label=Follow\"></a></div></td>\n",
     "    </tr>\n",
     "    <tr>\n",
     "        <td style=\"text-align: left;\">❓ Other Requests</d>\n",