add homebrew to docs

[oregonpillow]

Closes #63 Closes #49 (duplicate)

[oregonpillow]

tested with:

name: jekyll
services:
    minimal:
        volumes:
            - ./:/srv/jekyll
        stdin_open: true
        tty: true
        image: jekyll/jekyll:latest
        platform: linux/amd64
        ports:
         - 4000:4000
        command: jekyll serve --livereload

[oregonpillow]

@osy ?

[osy]

See #63