AMP roadmap page: Update list of WGs and sync it more often

## 🚀 Feature Request

### Problem
The AMP [roadmap page](https://amp.dev/community/roadmap/) is beloved by all of us engineers, and we'd like to use it for our weekly meetings. However, two problems prevent us from doing so:
1. The list of working groups has become outdated when compared to our [newly approved list of WGs](https://github.com/ampproject/meta/issues/65#issue-710629579).
2. The items visible on the page are not updated often enough to be useful because facilitators post new updates shortly before our weekly team meeting (10:30 am Pacific every Monday).

### Solution
1. Manually update the list of working groups to reflect the new list at https://github.com/ampproject/meta/issues/65.
2. Schedule an automatic refresh of the content at exactly 10:30 am Pacific, every Monday. This coincides with the start time of our weekly meetings.

Possible? Easy? (Thanks in advance!)

/cc @mrjoro and @kristoferbaxter in case you have additional comments.