Monorepo migration notes

If you are transitioning from the non-monorepo mattermost-server to the monorepo, the easiest way to do so is to move the old mattermost server folder to something like mattermost-server-old then re-clone mattermost-server. Then:

1. Copy over your old config

   cd server
   cp ../../mattermost-server-old/config/config.json ./config/

2. Copy over your developer config override

   cd server
   cp ../../mattermost-server-old/config.override.mk ./

3. Update your development Docker containers for the new location of the server folder:

   cd server
   make update-docker