chore(docs): add installation instructions

README.md

@@ -14,11 +14,28 @@ setlist-to-playlist --url https://www.setlist.fm/setlist/blink182/2024/autodromo
 
 ## Installation
 
-TBA
+### Step 1: downloading the binary
 
-## Architecture
+1. Download the latest release for your OS from the [releases page](https://github.com/mathcale/setlist-to-playlist/releases/latest)
+2. Extract the tarball to a folder in your PATH (like `$HOME/.local/bin` or `/usr/local/bin`)
+3. Run `setlist-to-playlist --help` to check if the installation was successful
 
-TBA
+### Step 2: Generating the Spotify API credentials
+
+1. Go to the [Spotify Developer Dashboard](https://developer.spotify.com/dashboard/applications)
+2. Click on "Create app" and fill in the required fields, but pay attention to the following:
+   - The `Redirect URIs` field **MUST** be `http://localhost:8080/callback`
+   - The `Web API` checkbox **MUST** be checked
+3. Copy the `Client ID` and `Client Secret` to a safe place
+
+### Step 3: Generating the Setlist.fm API key
+
+1. Go to the [Setlist.fm API page](https://www.setlist.fm/settings/apps) and fill in the required fields
+2. Copy the generated `API Key` to a safe place
+
+### Step 4: Configuring the CLI
+
+On the first run, the CLI will ask for the credentials you generated in the previous steps. Just copy and paste them when prompted and the CLI will store them in a TOML configuration file in your home directory (`$HOME/.config/setlist-to-playlist` on Linux and `$HOME/Library/Application Support/setlist-to-playlist` on macOS).
 
 ## Development