Update github issue templates, add related issues section

.github/ISSUE_TEMPLATE/bug_report.md

@@ -25,5 +25,8 @@ A clear and concise description of what actually happened.
 **Screenshots**
 If applicable, add screenshots to help explain your problem.
 
+**Related issues**
+Any other issues that are related to this one, link them here.
+
 **Additional context**
 Add any other context about the problem here. Maybe upload appropriate savegame files?

.github/ISSUE_TEMPLATE/feature_request.md

@@ -21,3 +21,6 @@ Please attach any screenshots of current behavior and mockups of desired behavio
 
 **Things to consider**
 What questions need to be addressed in order to implement this feature request?
+
+**Related issues**
+Any other issues that are related to this one, link them here.

.github/ISSUE_TEMPLATE/task.md

@@ -1,13 +1,15 @@
 ---
 name: Task
 about: Something needs to be implemented for this game to be feature complete as compared
-  to SE4.
+  to SE4 or just functionally complete in general.
 title: ''
 labels: task
 assignees: ''
 
 ---
 
 **What needs to be done?**
-
 Describe what needs to be done here.
+
+**Related issues**
+Any other issues that are related to this one, link them here.

.github/ISSUE_TEMPLATE/technical-debt.md

@@ -12,3 +12,6 @@ assignees: ''
 **How will this benefit us?**
 
 **What potential drawbacks are there to making this change?**
+
+**Related issues**
+Any other issues that are related to this one, link them here.