Fix links for files moved to .github folder.

.github/CONTRIBUTING.md

@@ -24,7 +24,7 @@ If you have questions about how to install or use ownCloud, please direct these
 
 Help us to maximize the effort we can spend fixing issues and adding new features, by not reporting duplicate issues.
 
-[template]: https://raw.github.com/owncloud/core/master/issue_template.md
+[template]: https://raw.github.com/owncloud/core/master/.github/issue_template.md
 [mailinglist]: https://mailman.owncloud.org/mailman/listinfo/owncloud
 [forum]: https://central.owncloud.org/
 [irc]: https://webchat.freenode.net/?channels=owncloud&uio=d4

.github/PULL_REQUEST_TEMPLATE.md

 <!--
 Thanks for submitting a change to ownCloud!
 
-This is the bug tracker for the Server component. Find other components at https://github.com/owncloud/core/blob/master/CONTRIBUTING.md#guidelines
+This is the bug tracker for the Server component. Find other components at https://github.com/owncloud/core/blob/master/.github/CONTRIBUTING.md#guidelines
 
 For fixing potential security issues please see https://owncloud.org/security/
 

.github/issue_template.md

 <!--
 Thanks for reporting issues back to ownCloud! This is the issue tracker of ownCloud, if you have any support question please check out https://owncloud.org/support
 
-This is the bug tracker for the Server component. Find other components at https://github.com/owncloud/core/blob/master/CONTRIBUTING.md#guidelines
+This is the bug tracker for the Server component. Find other components at https://github.com/owncloud/core/blob/master/.github/CONTRIBUTING.md#guidelines
 
 For reporting potential security issues please see https://owncloud.org/security/
 

settings/templates/help.php

@@ -28,7 +28,7 @@
 
 	<?php if($_['admin']) { ?>
 		<li>
-			<a href="https://github.com/owncloud/core/blob/master/CONTRIBUTING.md"
+			<a href="https://github.com/owncloud/core/blob/master/.github/CONTRIBUTING.md"
 				target="_blank" rel="noreferrer">
 				<?php p($l->t('Issue tracker')); ?> ↗
 			</a>