docs: add missing link to oapi-codegen reference in lab doc

docs/03-add-cli-command.md

@@ -1,6 +1,6 @@
 # Generate App Platform API Client Library
 
-The App Platform is API driven. It adhears to the [OpenAPI 3.0 specification](https://swagger.io/specification/v3/) and exposes an endpoint for users to access the Swagger web UI for documentation and testing―you've probably seen [these](https://petstore.swagger.io/?_gl=1*87igsc*_gcl_au*MTQzMDc3NTkwNS4xNzcxMDMxMDQ1) before. This standardization enables the use of tooling which can consume the JSON schema and auto-generate boilerplate code for us. In the Golang arena, One such tool is the remarkable [oapi-codegen]. We can use it to generate HTTP models, server-side code, as well as clients. The latter is what we'll focus on for this exercise.
+The App Platform is API driven. It adhears to the [OpenAPI 3.0 specification](https://swagger.io/specification/v3/) and exposes an endpoint for users to access the Swagger web UI for documentation and testing―you've probably seen [these](https://petstore.swagger.io/?_gl=1*87igsc*_gcl_au*MTQzMDc3NTkwNS4xNzcxMDMxMDQ1) before. This standardization enables the use of tooling which can consume the JSON schema and auto-generate boilerplate code for us. In the Golang arena, One such tool is the remarkable [oapi-codegen](https://github.com/oapi-codegen/oapi-codegen). We can use it to generate HTTP models, server-side code, as well as clients. The latter is what we'll focus on for this exercise.
 
 Let's get started by adding this tool to our arsenal. For systems running Go 1.24+, the offical project recommends installing it `go get -tool`, but the `go install` works as well. We won't dig into the reasons for picking one or the other, but if you're interested, a co-maintainer of the `oapi-codegen` project outlines it pretty well this [post](https://www.jvt.me/posts/2025/01/27/go-tools-124/).