Docs: Add notes for running tailwindcss:watch in Docker

[geetfun]

While running bin/rails tailwindcss:watch from within a Procfile, it was noticed that the command returns an exit 0 status if this is happening from within a Docker container.

See tailwindlabs/tailwindcss#5324 for same problem and solution.

This may present as a gotcha for those running their Rails app from docker-compose.yml. Suggestion here to add this useful piece of information in the README.

[paddy-hack]

Ran into this myself and found the same issue you mentioned 😅

[dixpac]

This is helpful 👍🏼 . But, maybe we don't need new sub-heading for this can we just add note about docker in the beginning where tailwindcss:watch is mentioned.

Somewhere around this paragraph:

When you're developing your application, you want to run Tailwind in watch mode, so changes are automatically reflected in the generated CSS output. You can do this either by running rails tailwindcss:watch as a separate process, or by running ./bin/dev which uses foreman to starts both the Tailwind watch process and the rails server in development mode.

[geetfun]

This is helpful 👍🏼 . But, maybe we don't need new sub-heading for this can we just add note about docker in the beginning where tailwindcss:watch is mentioned.

Good idea. I've moved it to your suggested paragraph where rails tailwindcss:watch is mentioned.