add a bit of docs

README.md

@@ -0,0 +1,24 @@
+# account.rs
+
+Reimplementation of the Nintendo Network Account System (NNAS) in Rust.
+
+# Requirements
+
+- Rust (rustup recommended)
+- A PostgreSQL database
+- An S3 bucket
+- An SMTP server
+
+For more info on configuring the server, check the .env.example file, it has comments that should help.
+
+# Building
+
+This step shouldn't be required once we start making official releases, but for now you need to build it yourself.
+You will need to set your database's connection URL in the environment variable DATABASE_URL with `export`. Without it, the server will not build.
+
+```bash
+export DATABASE_URL=postgresql://your-user:your-password@your-postgresql-server:5432/your-db
+```
+
+Once you have that set up, you should just be able to run `cargo build` and it will build to `target/account-server-rust`.
+