Readme and docs (#1155)

* update readme and doc

* one more

Author: zzstoatzz

README.md

@@ -2,29 +2,21 @@
 
 # Marvin
 
-Marvin is a Python framework for building agentic AI workflows. 
+Marvin is a Python framework for producing structured outputs and building agentic AI workflows.
 
-Marvin provides a structured, developer-focused framework for defining workflows and delegating work to LLMs, without sacrificing control or transparency:
+Marvin provides an intuitive API for defining workflows and delegating work to LLMs:
 
+- Cast, classify, extract, and generate structured data from any inputs.
 - Create discrete, observable **tasks** that describe your objectives.
 - Assign one or more specialized AI **agents** to each task.
 - Combine tasks into a **thread** to orchestrate more complex behaviors.
 
-
-> [!WARNING]
-> 
-> 🚧🚨 Marvin 3.x is under active development, reflected on the `main` branch of this repo. The API may undergo breaking changes, and documentation is still being updated (can be found at [marvin.mintlify.app](https://marvin.mintlify.app)).
-
 ## Installation
 
 Install `marvin`:
 
 ```bash
-# with pip
-pip install marvin
-
-# with uv
-uv add marvin
+uv pip install marvin
 ```
 
 Configure your LLM provider (Marvin uses OpenAI by default but natively supports [all Pydantic AI models](https://ai.pydantic.dev/models/)):

docs/functions/cast.mdx

@@ -117,16 +117,18 @@ print(f"{address.street}, {address.city}, {address.country}")
 Use instructions to control how text is interpreted and formatted:
 
 ```python
+from typing import Annotated
 import marvin
+from pydantic import Field
 
 phone = marvin.cast(
-    "call me at 1-800-555-0123",
-    str,
-    instructions="Extract just the phone number in XXX-XXXX format"
+    "call me at 800-555-0123",
+    Annotated[str, Field(pattern=r"\d{1}-\d{3}-\d{3}-\d{4}")],
+    instructions="extract the phone number and assume the country code is 1"
 )
 print(phone)
 ```
 
 ```python
-"555-0123"
+"1-800-555-0123"
 ``` 

docs/functions/generate.mdx

@@ -127,14 +127,13 @@ Generate lists and dictionaries:
 
 ```python
 import marvin
-from typing import List, Dict
 
 # Generate a list of strings
-ingredients = marvin.generate(List[str], instructions="Generate recipe ingredients")
+ingredients = marvin.generate(list[str], instructions="Generate recipe ingredients")
 print(ingredients)
 
 # Generate a dictionary
-menu = marvin.generate(Dict[str, float], instructions="Generate menu items with prices")
+menu = marvin.generate(dict[str, float], instructions="Generate menu items with prices")
 print(menu)
 ```