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/advanced-patching.md

@@ -0,0 +1,68 @@
+---
+title: Use Patching for Safe Workflow Upgrades
+impact: LOW
+impactDescription: Deploy breaking changes without disrupting in-progress workflows
+tags: patching, upgrade, versioning, migration
+---
+
+## Use Patching for Safe Workflow Upgrades
+
+Use `DBOS.patch()` to safely deploy breaking workflow changes. Breaking changes alter what steps run or their order.
+
+**Incorrect (breaking change without patch):**
+
+```python
+# Original
+@DBOS.workflow()
+def workflow():
+    foo()
+    bar()
+
+# Updated - breaks in-progress workflows!
+@DBOS.workflow()
+def workflow():
+    baz()  # Replaced foo() - checkpoints don't match
+    bar()
+```
+
+**Correct (using patch):**
+
+```python
+# Enable patching in config
+config: DBOSConfig = {
+    "name": "my-app",
+    "enable_patching": True,
+}
+DBOS(config=config)
+
+@DBOS.workflow()
+def workflow():
+    if DBOS.patch("use-baz"):
+        baz()  # New workflows use baz
+    else:
+        foo()  # Old workflows continue with foo
+    bar()
+```
+
+Deprecating patches after all old workflows complete:
+
+```python
+# Step 1: Deprecate (runs all workflows, stops inserting marker)
+@DBOS.workflow()
+def workflow():
+    DBOS.deprecate_patch("use-baz")
+    baz()
+    bar()
+
+# Step 2: Remove entirely (after all deprecated workflows complete)
+@DBOS.workflow()
+def workflow():
+    baz()
+    bar()
+```
+
+`DBOS.patch(name)` returns:
+- `True` for new workflows (started after patch deployed)
+- `False` for old workflows (started before patch deployed)
+
+Reference: [Patching](https://docs.dbos.dev/python/tutorials/upgrading-workflows#patching)