adjust docs to reflect that the setting is used all over the place

Author: noerw

docs/content/doc/advanced/config-cheat-sheet.en-us.md

@@ -171,7 +171,7 @@ The following configuration set `Content-Type: application/vnd.android.package-a
 ## UI (`ui`)
 
 - `EXPLORE_PAGING_NUM`: **20**: Number of repositories that are shown in one explore page.
-- `ISSUE_PAGING_NUM`: **20**: Number of issues that are shown in one page (for all pages that list issues).
+- `ISSUE_PAGING_NUM`: **20**: Number of issues that are shown in one page (for all pages that list issues, milestones, projects).
 - `MEMBERS_PAGING_NUM`: **20**: Number of members that are shown in organization members.
 - `FEED_MAX_COMMIT_NUM`: **5**: Number of maximum commits shown in one activity feed.
 - `FEED_PAGING_NUM`: **20**: Number of items that are displayed in home feed.