Add github action to generate "OSS Adopters" page

The "OSS Adopters" page is automagically generated based on network information in our git repos. The script `scripts/generate-adopters-info.sh` was a quick and dirty hack to create the page using the Python tool, `github-dependents-info`. Some headline adopters come from `data/adopters.json` and can be curated as desired.

We should automate this using a GitHub action to be executed periodically, so the data on the page is fresh.

Start by reading scripts/generate-adopters-info.sh and data/adopters.json to understand how the OSS Adopters page is generated and which data is curated. Add a periodic GitHub Actions workflow that runs the existing generation process and refreshes the page while preserving curated adopters.

Written by the indexing model from the issue text.