chore: fix three typos in README + comment (#959)

- README.md L35: image alt text "arcitecture" -> "architecture"
- README.md L159: image alt text "Atomatic Tracing" -> "Automatic Tracing"
- crates/common/src/api/open_ai.rs L56: comment "requried parameters" -> "required parameters"

Doc + comment only.

Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>

README.md

@@ -32,7 +32,7 @@ Plano solves this by moving core delivery concerns into a unified, out-of-proces
 Plano pulls rote plumbing out of your framework so you can stay focused on what matters most: the core product logic of your agentic applications. Plano is backed by [industry-leading LLM research](https://planoai.dev/research) and built on [Envoy](https://envoyproxy.io) by its core contributors, who built critical infrastructure at scale for modern worklaods.
 
 **High-Level Network Sequence Diagram**:
-![high-level network plano arcitecture for Plano](docs/source/_static/img/plano_network_diagram_high_level.png)
+![high-level network plano architecture for Plano](docs/source/_static/img/plano_network_diagram_high_level.png)
 
 **Jump to our [docs](https://docs.planoai.dev)** to learn how you can use Plano to improve the speed, safety and obervability of your agentic applications.
 
@@ -156,7 +156,7 @@ curl http://localhost:8001/v1/chat/completions \
 
 Every request is traced end-to-end with OpenTelemetry - no instrumentation code needed.
 
-![Atomatic Tracing](docs/source/_static/img/demo_tracing.png)
+![Automatic Tracing](docs/source/_static/img/demo_tracing.png)
 
 ### What You Didn't Have to Build