Add source field to each cheatpath to describe cheatsheet's source

[Lonenso]

Is your feature request related to a problem? Please describe.
I was trying to sync cheatsheets between devices, so I put my conf.yml to my dotfiles. Suddenly, I realized that I still have to sync the community's cheatsheets manually(clone it) because the config only describes cheatsheets' locations.

Describe the solution you'd like
Add source field to each cheatpath like below, then we may have the ability to init/update cheatsheets, then users don't need to clone the repo manually.

This gives cheat the ability to describe cheatsheet's source, cheat may be able to manage cheatsheets without this helper scripts

- name: community
  path: ~/cheatsheets/community
  source: https://github.com/cheat/cheatsheets.git    # <-- add this 
  tags: [ community ]
  readonly: true

Describe alternatives you've considered
Still needs to add a field to config to describe cheatsheet's source but let this helper scripts to manage cheatsheets.

I think this alternative have the minimum changes and more flexible.

• cheat: load/edit/save cheatsheets
• cheat helper scripts: init/update cheatsheets

init() {
  readarray d < <(yq -c '.cheatpaths[]' ~/.cheat.yml)  # here's a hard code for cheat's config, I think we need an command option to show what exactly the cheat is using. Just like nginx -t
  for c in "${d[@]}"; 
  do
      name="$(echo ${c} | yq -r '.name')"
      path="$(echo ${c} | yq -r '.path')"
      src="$( echo ${c} | yq -r '.source')"

      echo "Init $name"
      [ ! -d "$path" ] && git clone $src $path || :
  done
  echo "Finished init"
}