Couchbase Lite Binary Log Decoder Tool Install Guide

• PRD: binary log decoder tool

 Tasks:

1. Add a link under the "Tools and Add ons" section in the couchbase main downloads page. The link would point to a docs section (for example https://docs.couchbase.com/couchbase-lite/2.1/swift.html#logging)
2. Installation instructions for macOS, Windows, Linux. Similar to the tabbed format(https://docs.couchbase.com/sync-gateway/2.1/getting-started.html).
3. Document support matrix https://docs.google.com/spreadsheets/d/1wali82budYZrMQn7CIoEl6t7cCLNAHtfdcNVrGgJpR0/edit?ts=5c6cb35d#gid=834619294 
4. List of supported platforms: We have a single binary for all flavors of Linux but you can explicitly call out the flavors that we will support https://docs.google.com/spreadsheets/d/1wali82budYZrMQn7CIoEl6t7cCLNAHtfdcNVrGgJpR0/edit?ts=5c6cb35d#gid=834619294
5. Create a FEWD ticket with relevant binary links