Update README and github template (#186)

.github/ISSUE_TEMPLATE/subtask.yml

@@ -0,0 +1,29 @@
+name: Subtask
+description: "Propose a subtask for infinity"
+title: "[Subtask]: "
+labels: [subtask]
+
+body:
+  - type: textarea
+    attributes:
+      label: Parent Issue
+      description: Write the ID of the parent issue
+      placeholder: "Parent issue: #"
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Detail of Subtask
+      description: |
+        Describe the functions that this subtask should implement
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Describe implementation you've considered
+      description: A clear and concise description of implementation you've considered or investigated.
+    validations:
+      required: false
+