Update the warnings (#376)

* Add more explanation for 2.x tutorials
* Put alternatives for 1.x tutorials

Author: bilgeyucel

tutorials/01_Basic_QA_Pipeline.ipynb

@@ -7,7 +7,7 @@
    "source": [
     "# Tutorial: Build Your First Question Answering System\n",
     "\n",
-    "> This tutorial is based on Haystack 1.x. If you're using Haystack 2.0 and would like to follow the updated version of this tutorial, check out [Creating Your First QA Pipeline with Retrieval-Augmentation](https://haystack.deepset.ai/tutorials/27_first_rag_pipeline) and [Build an Extractive QA Pipeline](https://haystack.deepset.ai/tutorials/34_extractive_qa_pipeline). \n",
+    "> This tutorial is based on Haystack 1.x (`farm-haystack`). If you're using Haystack 2.x (`haystack-ai`) and would like to follow the updated version of this tutorial, check out [Creating Your First QA Pipeline with Retrieval-Augmentation](https://haystack.deepset.ai/tutorials/27_first_rag_pipeline) and [Build an Extractive QA Pipeline](https://haystack.deepset.ai/tutorials/34_extractive_qa_pipeline). \n",
     ">\n",
     "> For more information on Haystack 2.0, read the [Haystack 2.0 announcement](https://haystack.deepset.ai/blog/haystack-2-release).\n",
     "\n",

tutorials/02_Finetune_a_model_on_your_data.ipynb

@@ -7,6 +7,10 @@
    "source": [
     "# Tutorial: Fine-Tuning a Model on Your Own Data\n",
     "\n",
+    "> This tutorial is based on Haystack 1.x (`farm-haystack`). If you're using Haystack 2.x (`haystack-ai`), refer to the [Haystack 2.x tutorials](https://haystack.deepset.ai/tutorials) or [Haystack Cookbook](https://haystack.deepset.ai/cookbook)\n",
+    ">\n",
+    "> For more information on Haystack 2.x, read the [Haystack 2.0 announcement](https://haystack.deepset.ai/blog/haystack-2-release).\n",
+    "\n",
     "- **Level**: Intermediate\n",
     "- **Time to complete**: 15 minutes\n",
     "- **Nodes Used**: `FARMReader`\n",

tutorials/03_Scalable_QA_System.ipynb

@@ -7,6 +7,10 @@
    "source": [
     "# Tutorial: Build a Scalable Question Answering System\n",
     "\n",
+    "> This tutorial is based on Haystack 1.x (`farm-haystack`). If you're using Haystack 2.x (`haystack-ai`), refer to the [Haystack 2.x tutorials](https://haystack.deepset.ai/tutorials) or [Haystack Cookbook](https://haystack.deepset.ai/cookbook)\n",
+    ">\n",
+    "> For more information on Haystack 2.x, read the [Haystack 2.0 announcement](https://haystack.deepset.ai/blog/haystack-2-release).\n",
+    "\n",
     "- **Level**: Beginner\n",
     "- **Time to complete**: 20 minutes\n",
     "- **Nodes Used**: `ElasticsearchDocumentStore`, `BM25Retriever`, `FARMReader`\n",