add linear webhook example

Author: rushilpatel0

codegen-examples/examples/linear_webhooks/.env.template

@@ -0,0 +1,3 @@
+LINEAR_ACCESS_TOKEN="..."
+LINEAR_SIGNING_SECRET="..."
+LINEAR_TEAM_ID="..."

codegen-examples/examples/linear_webhooks/pyproject.toml

@@ -0,0 +1,12 @@
+[project]
+name = "linear-webhook-example"
+version = "0.1.0"
+description = "Linear webhook example for Codegen"
+requires-python = ">=3.13"
+dependencies = [
+    "modal>=0.73.25",
+ "codegen",
+]
+
+[tool.uv.sources]
+codegen = { git = "https://github.com/codegen-sh/codegen-sdk", rev = "rpatel/wip-events-decorator" }