Provide meaningful default shared folders

[jmuheim]

I'm unsure which folders I should share. At the time being, it's the following:

set :shared_dirs, fetch(:shared_dirs, []).push('log', 'tmp', 'public/uploads')

Maybe you should provide meaningful default shared folders? Instead of

# set :shared_dirs, fetch(:shared_dirs, []).push('somedir')

something like

# set :shared_dirs, fetch(:shared_dirs, []).push('log', 'tmp', 'public/uploads')

because for shared files you already do provide meaningful default ones:

# set :shared_files, fetch(:shared_files, []).push('config/database.yml', 'config/secrets.yml')

[arun057]

should probably include public/assets and vendor/bundle as well

[d4be4st]

@arun057 they are included by default

Will add to documentation