chore(docs): update readme and templates (#6646)

* update the readme and templates with the final project status.

.github/ISSUE_TEMPLATE.md

@@ -1,17 +1,5 @@
-The issues forum is __NOT__ for support requests. It is for bugs and feature requests only.
-Please read https://github.com/angular-ui/bootstrap/blob/master/CONTRIBUTING.md and search
-existing issues (both open and closed) prior to opening any new issue and ensure you follow the instructions therein.
+# PLEASE READ
 
-### Bug description:
+As per the [README](https://github.com/angular-ui/bootstrap/blob/master/README.md), this project is no longer being maintained.  Any issues entered will remain uninvestigated and unresolved.
 
-### Link to minimally-working plunker that reproduces the issue:
-
-### Steps to reproduce the issue:
-
-### Version of Angular, UIBS, and Bootstrap
-
-Angular:
-
-UIBS:
-
-Bootstrap:
+We thank you for your contributions over the years.  This library would not have been successful without them.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,5 @@
+# PLEASE READ
+
+As per the [README](https://github.com/angular-ui/bootstrap/blob/master/README.md), this project is no longer being maintained.  Any PRs entered will not be reviewed or merged and will remain open.
+
+We thank you for your contributions over the years.  This library would not have been successful without them.

README.md

@@ -1,3 +1,10 @@
+# Project Status (please read)
+Due to [Angular](https://angular.io)'s continued adoption, our creation of [the Angular version of this library](https://ng-bootstrap.github.io), and the the project maintainers' moving on to other things, this project is considered feature-complete and is no longer being maintained.
+
+We thank you for all your contributions over the years and hope you've enjoyed using this library as much as we've had developing and maintaining it.  It would not have been successful without them.
+
+-
+
 ### UI Bootstrap - [AngularJS](http://angularjs.org/) directives specific to [Bootstrap](http://getbootstrap.com)
 
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/angular-ui/bootstrap?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)