Update docs to reflect new setup processes and instructions based on rearchitecture

- Most important updates include the depedency requirement to setup Postgres when running/setting Khoj up locally
- Add instructiosn for Docker
- Shift to recommend desktop client and update instructions for how to configure Khoj for user

docs/obsidian.md

@@ -18,24 +18,15 @@
 
 
 ## Setup
-- *Make sure [python](https://realpython.com/installing-python/) and [pip](https://pip.pypa.io/en/stable/installation/) are installed on your machine*
 - *Ensure you follow the ordering of the setup steps. Install the plugin after starting the khoj backend. This allows the plugin to configure the khoj backend*
 
 ### 1. Setup Backend
-Open terminal/cmd and run below command to install and start the khoj backend
-- On Linux/MacOS
-  ```shell
-  python -m pip install khoj-assistant && khoj
-  ```
-
-- On Windows
-  ```shell
-  py -m pip install khoj-assistant && khoj
-  ```
+Follow the instructions in [the setup page](./setup.md?id=_1-install)
 
 ### 2. Setup Plugin
   1. Open [Khoj](https://obsidian.md/plugins?id=khoj) from the *Community plugins* tab in Obsidian settings panel
   2. Click *Install*, then *Enable* on the Khoj plugin page in Obsidian
+  3. Get an API key from the Khoj web settings page. Use this key to configure the Khoj plugin in Obsidian.
   3. [Optional] To enable Khoj Chat, set your [OpenAI API key](https://platform.openai.com/account/api-keys) in the Khoj plugin settings
 
 See [official Obsidian plugin docs](https://help.obsidian.md/Extending+Obsidian/Community+plugins) for details