support win dev by moving environment config

[ionous]

windows can't run bash scripts without linux for windows ( which imposes some extra headaches for shift development; setup of wsl, permission issues, etc. )

the bash script sets up the environment needed for docker compose to work ( which is why we can't use "docker compose" directly at the command line; but after this, we can. )

docker does, however, support a ".env" file next to the compose file just for this purpose.

changes:

• moved envvars from ./shift to .env
• for letsencrypt and eventimages, put the required production paths in shift.overrides.production ( because these two had/need special handling )
• moved local event images from /backend/eventimages to /app/eventimages . the latter is what "npm run dev" uses and makes fake event creation work inside docker ( really, dev should probably be using /bin/eventimages; and docker should be using a volume.... but that's a whole different can of tomatoes )
• added a new placeholder directory ./services/nginx/letsencrypt/. this placeholder is only used for development. previously mac/linux dev would use /tmp/letsencrypt just like production does; but windows can't use /tmp folders.
• removed unused envvars from thesecrets.example
• for windows users: added npm scripts for up, down, watch, and emails to mimic those commands from ./shift; and tweaked the npm build script to output hugo files into the expected docker location. ( npm run up and npm run down now work, and match shift up and shift down )
• updated the readme to describe the windows steps; and moved the old, probably inaccurate local netlify development steps from the readme to a separate doc file with notes
• new command: npm run docker-create-events -- which if docker is running, will create a handful of fake events inside mysql

fixed:

the node container in docker-compose.yml should have been using the EVENTIMAGES envvar just like nginx does:

shift-docs/docker-compose.yml

Line 17 in aa2dec3

- "${EVENTIMAGES}:/opt/backend/eventimages"

^ the ngnix container conf. vs, the current, not quite correct, node container conf:

shift-docs/docker-compose.yml

Line 100 in aa2dec3

- ./backend/eventimages/:/opt/backend/eventimages/

[ionous]

leaving this as a draft for now.
i still need to do some more testing on my windows and mac machines. and we will want to ensure that the docker version on production actually supports env files(!) before using this there.

[nolessafool]

Maybe we can work with @aaronminnick since he's got the windows. I feel like we want to finish up the work in #772 and then #774 before we continue down this path, though - does that make sense to you @ionous ?