Added linked issues to PR template (#793)

This PR adds linked issues section to PR description

.github/pull_request_template.md

@@ -1,15 +1,19 @@
 ## Changes
-
 <!-- Summary of your changes that are easy to understand. Add screenshots when necessary -->
 
+### Linked issues
+<!-- DOC: Link issue with a keyword: close, closes, closed, fix, fixes, fixed, resolve, resolves, resolved. See https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword -->
+
+Resolves #..
+
 ### Functionality 
 
 - [ ] added relevant user documentation
 - [ ] added new CLI command
 - [ ] modified existing command: `databricks labs ucx ...`
 - [ ] added a new workflow
 - [ ] modified existing workflow: `...`
-- [ ] added new table
+- [ ] added a new table
 - [ ] modified existing table: `...`
 
 ### Tests