Add Open Source Starter Lab to project list

Open Source Starter Lab is a beginner-friendly repository with curated good first issues for Git, GitHub, pull requests, CI, TypeScript CLI work, and maintainer practice.

Repo: https://github.com/P-r-e-m-i-u-m/open-source-starter-lab

Suggested query:

```text
repo:P-r-e-m-i-u-m/open-source-starter-lab is:issue is:open label:"good first issue"
```

Start by locating the project-list data and a nearby entry, then review how listed repositories are represented. Add the supplied repository and query without changing the provided details, and verify that it appears in the list and links to the stated GitHub URL.

Written by the indexing model from the issue text.