Update issue templates

Author: nfalco79

.github/ISSUE_TEMPLATE/github-issue-tracker-has-been-dismissed-.md

@@ -0,0 +1,13 @@
+---
+name: 'GitHub issue tracker has been dismissed '
+about: Please report new issue of this plugin to JIRA issue tracker at https://issues.jenkins.io
+  rather than GitHub.
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+Please report new issue of this plugin to JIRA issue tracker at https://issues.jenkins.io rather than GitHub.
+
+More information at https://github.com/jenkinsci/bitbucket-branch-source-plugin/blob/master/README.md#issue-tracking-where-file-new-issues.

.github/ISSUE_TEMPLATE/github-issue-tracker-has-been-dismissed.md

@@ -0,0 +1,13 @@
+---
+name: GitHub issue tracker has been dismissed
+about: Please report new issue of this plugin to JIRA issue tracker at https://issues.jenkins.io
+  rather than GitHub.
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+Please report new issue of this plugin to JIRA issue tracker at https://issues.jenkins.io rather than GitHub.
+
+More information at https://github.com/jenkinsci/bitbucket-branch-source-plugin/blob/master/README.md#issue-tracking-where-file-new-issues.