[examples] Added basic tensorflow example (#989)

## Summary
title says it.

## How was it tested?
- `cd devbox/examples/data_science/tensorflow/`
- `devbox shell`
- `python3 main.py`

Author: mohsenari

examples/data_science/tensorflow/README.md

@@ -0,0 +1,11 @@
+# Tensorflow application
+
+Simple Tensorflow sample project with Devbox.
+
+## Setup
+
+- Make sure to have [devbox installed](https://www.jetpack.io/devbox/docs/quickstart/#install-devbox)
+- Clone this repo: `git clone https://github.com/jetpack-io/devbox.git`
+- `cd devbox/examples/data_science/tensorflow/`
+- `devbox shell`
+- `python3 main.py`

examples/data_science/tensorflow/devbox.json

@@ -0,0 +1,16 @@
+{
+  "packages": [
+    "python310",
+    "python310Packages.pip",
+    "stdenv.cc.cc.lib"
+  ],
+  "shell": {
+    "init_hook": [
+      "source $VENV_DIR/bin/activate",
+      "pip install -r requirements.txt"
+    ]
+  },
+  "nixpkgs": {
+    "commit": "f80ac848e3d6f0c12c52758c0f25c10c97ca3b62"
+  }
+}

examples/data_science/tensorflow/main.py

@@ -0,0 +1,4 @@
+import tensorflow as tf
+
+# Simple python script using Tensorflow
+print(tf.reduce_sum(tf.random.normal([1000, 1000])))

examples/data_science/tensorflow/requirements.txt

@@ -0,0 +1 @@
+tf-nightly