diff --git a/README.md b/README.md
index bbb6e48..decdacd 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,152 @@
-# freelance_invoice
+# Freelance Invoice
+
+is a simple command line tool to generate invoices for freelance work. It uses a simple template system based
+on `jinja2` to generate the
+invoice in HTML and then converts it to a PDF using `xhtml2pdf`.
+
+## inatallation
+
+Use python venv:
+
+```bash
+python -m venv venv
+source venv/bin/activate
+``` 
+
+Install the requirements:
+
+```bash
+pip install -r requirements.txt
+```
+
+## usage
+
+There are two yaml files describing your invoice:
+
+- `invoice.yaml` contains the invoice data
+- `envelope.yaml` contains the address data of the sender and the recipient
+
+The invoice data is read from the `invoice.yaml` file and the address data is read from the `envelope.yaml` file. The
+invoice data is then used to fill in the invoice template and the address data is used to fill in the address fields of
+the invoice.
+
+Some data are globaly available from the envelope template. Some of them can be overriden by the invoice template.
+
+invoice.yaml - The Name of the invoice file is used as the invoice number but you are free to override it in the
+invoice.yaml file.
+
+```yaml
+Id: RG004712 # overrides the file name as invlice Number
+CustomerId: KD01234 # The customer id is used to identify the customer and is beeing looked up in the envelope.yaml file.
+InvoiceDate: 2023-12-23 # The date of the invoice. If not set the current date is used.
+
+Positions:
+  - Title: "Zuckerwatte fressen Ganz besonders langer Text"
+    SubTitle: "Leistungszeitraum: 11/2022"
+    PricePerUnit: 100 # The price per unit is taken from the envelope.yaml file using the customer id but can be overriden here.
+    Quantity: 100
+
+  - Title: "Aschlecken"
+    SubTitle: "Leistungszeitraum: 11/2022"
+    PricePerUnit: 99.99
+    Quantity: 12
+
+  - Title: "Aschkriechen"
+    SubTitle: "Leistungszeitraum: 10/2022"
+    PricePerUnit: 77.88
+    Quantity: 3
+```
+
+envelope.yaml
+
+```yaml
+AddressContent:
+  # AddressBoxSender is is used as the sender address in the letter head inside the address windows.
+  AddressBoxSender: "Abs.: Torsten Ueberschar - Pfarrweg 1 - 57439 Attendorn"
+  # The Content is a place to put your personal data. E.G. it is used in the footer of the invoice.
+  # you may put markdown in here.
+  Contents:
+    - Text: |
+        ![logo](test_data/templates/images/logo.svg)  
+        Torsten Ueberschar  
+        Pfarrweg 1  
+        57439 Attendorn
+    - Text: |
+        **Kontakt**  
+        tu@uesome.de   
+        +49 2734 4239271
+    - Text: |
+        **Steuern**  
+        USt-IdNr.: DE313460724
+    - Text: |
+        **Bankverbindung**  
+        Torsten Ueberschar   
+        DE67 1001 1001 2626 8627 86   
+        NTSBDEB1XXX   
+        N26 Bank GmbH   
+
+# The Invoice field is used to put default values for the invoice. You may override them in the invoice.yaml file.    
+Invoice:
+  Vat: 19.0
+  Introduction: |
+    ### Rechnung 
+
+    *Sehr geehrte Damen und Herren*,
+
+    für folgende in Ihrem Auftrag ausgeführten Leistungen erlaube ich mir zu berechnen
+
+  Footer: |
+    Bitte überweisen Sie den Rechnungsbetrag unter Angabe der Rechnungsnummer auf mein Konto bis zum %%ZahlungsZiel%%.
+
+    Mit freundlichen Grüßen
+
+    *Torsten Uebeschar*
+
+# Customers is a list of customers. The customer id is used to identify the customer and is beeing looked up in the invoice.yaml file.    
+Customers:
+  - CustomerId: KD01234
+    PricePerUnit: 88.88
+    DueDate: 30 # DueDate is the number of days the customer has to pay the invoice.
+    # The AddressField is used to fill in the address field window of the invoice.
+    AddressField: |
+      Klaus Peter Klausen  
+      Am Klausenhof 1  
+      04711 Klausenhausen
+```
+
+```bash
+python src/main.py --help
+Simple invoice generator for freelancers and small businesses by Torsten Ueberschar
+
+usage: main.py [-h] -b BASE -i INVOICE [-e ENVELOPE] [-t TEMPLATE]
+
+Read invoice and envelope data from yaml file
+
+options:
+  -h, --help            show this help message and exit
+  -b BASE, --base BASE  base directory for invoice and envelope files
+  -i INVOICE, --invoice INVOICE
+                        Invoice file name
+  -e ENVELOPE, --envelope ENVELOPE
+                        Envelope file name
+  -t TEMPLATE, --template TEMPLATE
+                        directory for template files
+```
+
+## example
+
+```bash
+python src/main.py -b test_data -i invoice.yaml -e envelope.yaml -t test_data/templates
+```
+
+## to do
+
+- make image path in invoice.yaml relative to invoice.yaml
+- find out how to move an image to the right place in the pdf
+
+## see also
+
+https://xhtml2pdf.readthedocs.io/en/latest/index.html
+
+https://jinja.palletsprojects.com/
 
diff --git a/test_data/envelope.yaml b/test_data/envelope.yaml
index 05d7283..008cead 100644
--- a/test_data/envelope.yaml
+++ b/test_data/envelope.yaml
@@ -1,7 +1,3 @@
-Config:
-  DefaultFont: Barlow Semi Condensed
-  MonoFont: Barlow Semi Condensed
-  
 AddressContent:
   LogoFile: Images/logo.svg
   AddressBoxSender: "Abs.: Torsten Ueberschar - Pfarrweg 1 - 57439 Attendorn"