add documentation issue template

Author: edwardchalstrey1

.github/ISSUE_TEMPLATE/documentation_improvement.yml

@@ -0,0 +1,18 @@
+name: Documentation Improvement
+description: Suggest a change to the draw_tree documentation.
+title: "[Documentation]: "
+labels: ["documentation"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to fill out this documentation improvement request!
+  - type: textarea
+    id: request-details
+    attributes:
+      label: Requested documentation improvement
+      description: Please provide details about the documentation improvement you would like to see.
+      placeholder: Describe the documentation improvement in detail.
+      value: "A documentation improvement suggestion!"
+    validations:
+      required: true