Update behavior for the infinite scroll pagination without the list count
Problem
Currently, the behavior guidelines for infinite scroll using the pagination component require showing the list count along with the spinner when loading the next page. However, sometimes this showing the list count can be redundant or inefficient in terms of user experience, performance, or technical requirements.
See also relevant discussion in https://gitlab.com/gitlab-org/gitlab-ce/issues/65285#note_211876632.
Proposal
Let's add a small section within the behavior guidelines for the infinite scroll that make list count optional when needed. Also, maybe it's worth updating the specs to include this subtle variation.
Edited by George Tsiolis