Feature Request: Smart Case / Case Sensitive Search

[Penguin-Polity]

It would be nice if the search capabilities ("/" and "s") allowed for smart-case and case-insensitive matching via configuration in addition to the regex flag (i.e., ?i). Ideally, the search function would accept a parameter that specified case-sensitive, case-insensitive, or smart-case, allowing for the end-users to configure the search type using keymap configuration.

There is a note about smart-case search on #299, but I didn't see any issue created for it specifically. Thanks for this great extension.