Add examples for group sizing #314
Description
Describe the feature you'd like
Add examples under the group size header in the documentation for what numbers to put and how that will split groups up.
Pre-existing Issue or Justification
https://jury.mikz.dev/docs/usage/admin/groups#number-and-size-of-groups
This may be confusing for people--ie. some may think that it means a proportion of projects not the raw group numbers.
Additional context
No response