Proper "24 Pull Requests" title across the site and locales

proper 24PR branding for events text

I felt using 24pullrequests did not look well.. Does this make sense? :smile:

switch to 24 Pull Requests

switching to **24 Pull Requests** everywhere

fix 24 Pull Requests title in nb locale

Update zh_Hans.yml

Update zh_Hant.yml
Merge pull request #702 from steverob/patch-2

proper 24PR branding for events text