fix: issue templates

Author: scastillo-jp

.github/ISSUE_TEMPLATE/back-end.md

@@ -2,7 +2,7 @@
 name: Back end
 about: new tasks of Back-end
 title: BACK-END
-labels: ''
+labels: mvp, nice-to-have, tech-debt, enhancement
 assignees: ''
 
 ---

.github/ISSUE_TEMPLATE/bug_report.md

@@ -2,7 +2,7 @@
 name: Bug report
 about: Create a report to help us improve
 title: BUG
-labels: low
+labels: low, medium, high
 assignees: ''
 
 ---

.github/ISSUE_TEMPLATE/ui-task.md

@@ -2,7 +2,7 @@
 name: UI task
 about: new tasks of UI
 title: UI TASK
-labels: ''
+labels: mvp, nice-to-have, tech-debt, enhancement
 assignees: ''
 
 ---