docs: add python installation instructions

This commit adds the python installation instruction for
windows, macos, and linux to the backend dev environment setup page.

[SCSE-22]

Author: ztjhz

docs/backend/_python-linux.mdx

@@ -0,0 +1,36 @@
+### Ubuntu
+
+[deadsnakes PPA](https://launchpad.net/~deadsnakes/+archive/ubuntu/ppa) contains more recent Python versions packaged for Ubuntu.
+
+```bash
+$ sudo apt-get install software-properties-common
+$ sudo add-apt-repository ppa:deadsnakes/ppa
+$ sudo apt-get update
+$ sudo apt-get install python3.8
+```
+
+### Other Linux distribution
+
+If you are using other Linux distribution, `Python 3` is most likely preinstalled. If not, use your distribution's package manager to install it.
+
+For example, on Fedora, you would use `dnf`:
+
+```bash
+$ sudo dnf install python3
+```
+
+And on ArchLinux, you would use `pacman`:
+
+```bash
+$ sudo pacman -S python
+```
+
+To check if it is installed correctly:
+
+```bash
+python --version
+# Python 3.10.7
+# OR
+py --version
+#Python 3.10.7
+```

docs/backend/_python-macos.mdx

@@ -0,0 +1,14 @@
+1. Download the `Python` installer package from the [official Python website](https://www.python.org/downloads/)
+1. It should detect your operating system and show a yellow download button. If it doesn’t, click the `windows` link and choose the latest Python release.
+1. Once the download is complete, double-click the package to start installing `Python`. Follow the installation steps with the default settings.
+1. Once installation is complete, you have python installed on your system!
+
+To check if it is installed correctly:
+
+```bash
+python --version
+# Python 3.10.7
+# OR
+py --version
+#Python 3.10.7
+```

docs/backend/_python-windows.mdx

@@ -0,0 +1,14 @@
+1. Download the `Python` installer package from the [official Python website](https://www.python.org/downloads/)
+1. It should detect your operating system and show a yellow download button. If it doesn’t, click the `windows` link and choose the latest Python release.
+1. Once the download is complete, double-click the package to start installing `Python`. Follow the installation steps with the default settings.
+1. Once installation is complete, you have python installed on your system!
+
+To check if it is installed correctly:
+
+```bash
+python --version
+# Python 3.10.7
+# OR
+py --version
+#Python 3.10.7
+```

docs/backend/env-setup.mdx

@@ -4,6 +4,32 @@ sidebar_position: 1
 
 # Environment Setup
 
+```mdx-code-block
+import OsTabs from "@site/src/components/DocsFeatures/OsTabs.tsx"
+```
+
 Backend devs should have the following installed and configured as described below:
 
-## Python 3.x
+## Install `Python 3.x`
+
+```mdx-code-block
+import PythonWindows from "./_python-windows.mdx"
+import PythonMacOS from "./_python-macos.mdx"
+import PythonLinux from "./_python-linux.mdx"
+
+<OsTabs
+    windows={<PythonWindows />}
+    macos={<PythonMacOS />}
+    linux={<PythonLinux />}
+/>
+```
+
+## Install `poetry`
+
+## Install `nvm` & `node.js`
+
+Follow the instructions to install `nvm` & `node.js` [here](/docs/getting-started/node-nvm)
+
+## Install serverless cli
+
+## Install dynamodb offline