⚰️ remove synchronous support for material certificate (#223)

Author: sebastianMindee

docs/extras/code_samples/material_certificate_v1.txt

@@ -29,6 +29,37 @@ print(result.document)
 
 **Output (RST):**
 ```rst
+########
+Document
+########
+:Mindee ID: cfa20a58-20cf-43b6-8cec-9505fa69d1c2
+:Filename: default_sample.jpg
+
+Inference
+#########
+:Product: mindee/international_id v2.0
+:Rotation applied: No
+
+Prediction
+==========
+:Document Type: IDENTIFICATION_CARD
+:Document Number: 12345678A
+:Surnames: MUESTRA
+           MUESTRA
+:Given Names: CARMEN
+:Sex: F
+:Birth Date: 1980-01-01
+:Birth Place: CAMPO DE CRIPTANA CIUDAD REAL ESPANA
+:Nationality: ESP
+:Personal Number: BAB1834284<44282767Q0
+:Country of Issue: ESP
+:State of Issue: MADRID
+:Issue Date:
+:Expiration Date: 2030-01-01
+:Address: C/REAL N13, 1 DCHA COLLADO VILLALBA MADRID MADRID MADRID
+:MRZ Line 1: IDESPBAB1834284<44282767Q0<<<<
+:MRZ Line 2: 8001010F1301017ESP<<<<<<<<<<<3
+:MRZ Line 3: MUESTRA<MUESTRA<<CARMEN<<<<<<<
 ```
 
 # Field Types

docs/extras/guide/international_id_v2.md

@@ -3,7 +3,7 @@ title: Material Certificate OCR Python
 ---
 The Python OCR SDK supports the [Material Certificate API](https://platform.mindee.com/mindee/material_certificate).
 
-Using the [sample below](https://github.com/mindee/client-lib-test-data/blob/main/products/material_certificate/default_sample.jpg), we are going to illustrate how to extract the data that we want using the OCR SDK.
+The [sample below](https://github.com/mindee/client-lib-test-data/blob/main/products/material_certificate/default_sample.jpg) can be used for testing purposes.
 ![Material Certificate sample](https://github.com/mindee/client-lib-test-data/blob/main/products/material_certificate/default_sample.jpg?raw=true)
 
 # Quick-Start
@@ -27,10 +27,6 @@ print(result.document)
 # print(result.document.inference.prediction)
 ```
 
-**Output (RST):**
-```rst
-```
-
 # Field Types
 ## Standard Fields
 These fields are generic and used in several products.

docs/extras/guide/material_certificate_v1.md

@@ -120,7 +120,7 @@ class CommandConfig(Generic[TypeInference]):
     "material-certificate": CommandConfig(
         help="Material Certificate",
         doc_class=product.MaterialCertificateV1,
-        is_sync=True,
+        is_sync=False,
         is_async=True,
     ),
     "multi-receipts": CommandConfig(