Add install readme file

.goreleaser.yml

@@ -24,6 +24,6 @@ builds:
 archives:
   - format: tar.gz
     files:
-      - config.toml.sample
       - README.md
+      - INSTALL.md
       - LICENSE

INSTALL.md

@@ -0,0 +1,5 @@
+# Install and run
+
+- Run `./listmonk --new-config` to generate a sample `config.toml` and add your configuration (SMTP and Postgres DB credentials primarily).
+- `./listmonk --install` to setup the DB.
+- Visit `http://localhost:9000`.