Improve Khoj with DB setup instructions in the Django app readme (for now)

src/app/README.md

@@ -17,16 +17,26 @@ docker-compose up
 
 ## Setup (Local)
 
-### Install dependencies
+### Install Postgres (with PgVector)
+
+#### MacOS
+- Install the [Postgres.app](https://postgresapp.com/).
+
+#### Debian, Ubuntu
+From [official instructions](https://wiki.postgresql.org/wiki/Apt)
 
 ```bash
-pip install -e '.[dev]'
+sudo apt install -y postgresql-common
+sudo /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh
+sudo apt install postgres-16 postgresql-16-pgvector
 ```
 
-### Setup the database
+#### Windows
+- Use the [recommended installer](https://www.postgresql.org/download/windows/)
 
-1. Ensure you have Postgres installed. For MacOS, you can use [Postgres.app](https://postgresapp.com/).
-2. If you're not using Postgres.app, you may have to install the pgvector extension manually. You can find the instructions [here](https://github.com/pgvector/pgvector#installation). If you're using Postgres.app, you can skip this step. Reproduced instructions below for convenience.
+#### From Source
+1. Follow instructions to [Install Postgres](https://www.postgresql.org/download/)
+2. Follow instructions to [Install PgVector](https://github.com/pgvector/pgvector#installation) in case you need to manually install it. Reproduced instructions below for convenience.
 
 ```bash
 cd /tmp
@@ -35,32 +45,50 @@ cd pgvector
 make
 make install # may need sudo
 ```
-3. Create a database
 
-### Create the khoj database
+### Create the Khoj database
 
+#### MacOS
 ```bash
 createdb khoj -U postgres
 ```
 
-### Make migrations
+#### Debian, Ubuntu
+```bash
+sudo -u postgres createdb khoj
+```
 
-This command will create the migrations for the database app. This command should be run whenever a new model is added to the database app or an existing model is modified (updated or deleted).
+- [Optional] To set default postgres user's password
+  - Execute `ALTER USER postgres PASSWORD 'my_secure_password';` using `psql`
+  - Run `export $POSTGRES_PASSWORD=my_secure_password` in your terminal for Khoj to use it later
+
+### Install Khoj
+
+```bash
+pip install -e '.[dev]'
+```
+
+### Make Khoj DB migrations
+
+This command will create the migrations for the database app. This command should be run whenever a new db model is added to the database app or an existing db model is modified (updated or deleted).
 
 ```bash
 python3 src/manage.py makemigrations
 ```
 
-### Run migrations
+### Run Khoj DB migrations
 
 This command will run any pending migrations in your application.
 ```bash
 python3 src/manage.py migrate
 ```
 
-### Run the server
+### Start Khoj Server
 
 While we're using Django for the ORM, we're still using the FastAPI server for the API. This command automatically scaffolds the Django application in the backend.
+
+*Note: Anonymous mode bypasses authentication for local, single-user usage.*
+
 ```bash
-python3 src/khoj/main.py
+python3 src/khoj/main.py --anonymous-mode
 ```