feat: add DBOS skills for TypeScript, Python, and Go (#94)

Add three DBOS SDK skills with reference documentation for building
reliable, fault-tolerant applications with durable workflows.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

skills/dbos-python/references/pattern-classes.md

@@ -0,0 +1,61 @@
+---
+title: Use DBOS Decorators with Classes
+impact: MEDIUM
+impactDescription: Enables stateful workflow patterns with class instances
+tags: classes, dbos_class, instance, oop
+---
+
+## Use DBOS Decorators with Classes
+
+DBOS decorators work with class methods. Workflow classes must inherit from `DBOSConfiguredInstance`.
+
+**Incorrect (missing class setup):**
+
+```python
+class MyService:
+    def __init__(self, url):
+        self.url = url
+
+    @DBOS.workflow()  # Won't work without proper setup
+    def fetch_data(self):
+        return self.fetch()
+```
+
+**Correct (proper class setup):**
+
+```python
+from dbos import DBOS, DBOSConfiguredInstance
+
+@DBOS.dbos_class()
+class URLFetcher(DBOSConfiguredInstance):
+    def __init__(self, url: str):
+        self.url = url
+        # instance_name must be unique and passed to super()
+        super().__init__(instance_name=url)
+
+    @DBOS.workflow()
+    def fetch_workflow(self):
+        return self.fetch_url()
+
+    @DBOS.step()
+    def fetch_url(self):
+        return requests.get(self.url).text
+
+# Instantiate BEFORE DBOS.launch()
+example_fetcher = URLFetcher("https://example.com")
+api_fetcher = URLFetcher("https://api.example.com")
+
+if __name__ == "__main__":
+    DBOS.launch()
+    print(example_fetcher.fetch_workflow())
+```
+
+Requirements:
+- Class must be decorated with `@DBOS.dbos_class()`
+- Class must inherit from `DBOSConfiguredInstance`
+- `instance_name` must be unique and passed to `super().__init__()`
+- All instances must be created before `DBOS.launch()`
+
+Steps can be added to any class without these requirements.
+
+Reference: [Python Classes](https://docs.dbos.dev/python/tutorials/classes)