Chat space and useful references

I'll see about adding some of these to our quick links!

   - Terminology: https://datatracker.ietf.org/doc/rfc8793/
   - Chat Space (Matrix): https://matrix.to/#/#icn:matrix.org
   - Convergence effort discussions
      -
      https://mailarchive.ietf.org/arch/browse/icnrg/?gbt=1&index=HtJfO_A6wm9X9aIkjtSqOhZXOs0
      -
      https://www.lists.cs.ucla.edu/pipermail/ndn-interest/2025-April/003079.html
   - Named Data Networking: https://named-data.net/project/archoverview/
      - 101: https://github.com/named-data/ndn-101
      - Discussion list:
      https://www.lists.cs.ucla.edu/mailman/listinfo/ndn-interest
   - Content Centric Networking:
   https://web.archive.org/web/20141030154453/http://www.ccnx.org:80/architecture-overview/
      - IRTF specification body: https://www.irtf.org/icnrg.html
      - Discussion list:
      https://mailman3.irtf.org/mailman3/lists/icnrg@irtf.org/