docs: Improve contributing instructions

Author: CPlusPatch

.github/copilot-instructions.md

@@ -11,10 +11,11 @@ Versia Server is built using the following technologies:
 
 - [Bun](https://bun.sh) - A JavaScript runtime similar to Node.js, but faster and with more features
 - [PostgreSQL](https://www.postgresql.org/) - A relational database
-  - [`pg_uuidv7`](https://github.com/fboulnois/pg_uuidv7) - A PostgreSQL extension that provides a UUIDv7 data type
+- [Drizzle ORM](https://orm.drizzle.team/) - An ORM for TypeScript and JavaScript, used for database interactions
 - [Docker](https://www.docker.com/) - A containerization platform, used for development and deployment
 - [Sharp](https://sharp.pixelplumbing.com/) - An image processing library, used for fast image resizing and converting
 - [TypeScript](https://www.typescriptlang.org/) - A typed superset of JavaScript
+- [Biome](https://biomejs.dev) - A code formatter and linter, used to enforce a consistent code style
 
 ## Getting Started
 
@@ -36,7 +37,7 @@ git clone https://github.com/versia-pub/server.git
 bun install
 ```
 
-1. Set up a PostgreSQL database (you need a special extension, please look at [the database documentation](https://server.versia.pub/setup/database))
+1. Set up a PostgreSQL database.
 
 2. Copy the `config/config.example.toml` file to `config/config.toml` and edit it to set up the database connection and other settings.
 
@@ -104,6 +105,12 @@ bun lint --write
 
 You can also install the Biome Visual Studio Code extension and have it format your code automatically on save.
 
+### Conventions
+
+- We always use ESM and the very latest TypeScript/JavaScript features available in Bun.
+- We use double quotes for strings and four spaces for indentation.
+- We try to use JSDoc comments for all functions and classes, and we use explicit type annotations for all variables and function return values.
+
 ### TypeScript
 
 Linting should not be ignored, except if they are false positives, in which case you can use a comment to disable the rule for the line or the file. If you need to disable a rule, please add a comment explaining why.
@@ -139,6 +146,20 @@ Documentation for the Versia protocol is available on [versia.pub](https://versi
 
 This project should not need much documentation, but if you think that something needs to be documented, please add it to the README, docs or contribution guide.
 
+## Code structure
+
+This project uses a monorepo structure with Bun as the package manager. Packages are located in the `packages` directory:
+- Packages that start with `@versia-server/` are utility packages for the server, such as the database and tables packages.
+- Packages that start with `@versia` are published packages that can be used by third-party developers, such as the `@versia/client` package.
+
+### ORM
+
+Our codebase uses Drizzle as an ORM, which is exposed in the `@versia-server/kit/db` and `@versia-server/kit/tables` packages.
+
+### API and worker
+
+The app has two modes: worker and API. The worker mode is used for background tasks, while the API mode serves HTTP requests. The entry point for the worker is `worker.ts`, and for the API, it is `api.ts`.
+
 ## Reporting bugs
 
 If you find a bug, please open an issue on GitHub. Please make sure to include the following information: