doc: add lib lifecycles to readme (#27)

README.md

@@ -1,7 +1,6 @@
 # Boltz Python Client
 Boltz Client in Python, implementing mainchain and liquid submarine swaps. Used by e.g. https://github.com/lnbits/boltz.
 
-
 # CLI
 ```console
 $ boltz --help
@@ -24,6 +23,56 @@ Commands:
 ```
 install the latest release from [PyPI](https://pypi.org/project/boltz-client) via `pip install boltz_client`.
 
+# LIB
+### initialize the client
+```python
+from boltz_client import BoltzClient, BoltzConfig
+config = BoltzConfig() # default config
+client = BoltzClient(config, "BTC/BTC")
+```
+### lifecycle swap
+```python
+pr = create_lightning_invoice(100000) # example function to create a lightning invoice
+refund_privkey_wif, swap = client.create_swap(pr)
+print(f"pay this amount: {swap.expectedAmount}")
+print(f"to this address: {swap.address}")
+# when you pay the amount the invoice will be settled after the boltz claimed the swap
+```
+if swap fails you can refund like this
+```python
+# example function to create an onchain address
+onchain_address = create_onchain_address()
+txid = await client.refund_swap(
+    boltz_id=swap.id,
+    privkey_wif=refund_privkey_wif,
+    lockup_address=swap.address,
+    receive_address=onchain_address,
+    redeem_script_hex=swap.redeemScript,
+    timeout_block_height=swap.timeoutBlockHeight,
+)
+```
+
+### lifecycle reverse swap
+```python
+claim_privkey_wif, preimage_hex, swap = client.create_reverse_swap(50000)
+# example function to pay the invoice
+pay_task = asyncio.create_task(pay_invoice(swap.invoice))
+# example function to create an onchain address
+new_address = create_onchain_address()
+task = asyncio.create_task(client.claim_reverse_swap(
+    boltz_id=swap.id,
+    receive_address=new_address,
+    lockup_address=swap.lockupAddress,
+    redeem_script_hex=swap.redeemScript,
+    blinding_key=swap.blindingKey,
+    privkey_wif=claim_privkey_wif,
+    preimage_hex=preimage_hex,
+    zeroconf=True,
+))
+txid = await task
+await pay_task
+```
+
 
 # development