Quick start (English):
1) Copy .env.example to .env and set DB + admin password.
2) composer install
3) Create DB and import sql/schema.sql
4) Open /public/index.php -> login
5) Create a company
6) Add fields: InvoiceNo, InvoiceDate, SellerName, BuyerName, Terms
7) Upload storage/sample_template.docx as template
8) Create invoice, add items, generate DOCX