Update and rename milestone.md to epic.md (#681)

Aligning convention as per https://github.com/waku-org/pm/pull/45

.github/ISSUE_TEMPLATE/epic.md

@@ -0,0 +1,40 @@
+---
+name: Epic
+about: Track Epic
+title: "[Epic] "
+labels: epic
+assignees: ''
+
+---
+
+<!-- Please ensure you are assigning the matching milestone label to the epic -->
+<!-- All _active_ (being worked on) epics MUST have an owner (GitHub assignee) -->
+
+**Planned start date**:
+**Due date**:
+
+# Summary
+
+<!-- Provide a high level summary of the Epic -->  
+
+# Acceptance Criteria
+
+<!-- describe the deliverable of this epic and its attributes in plain English -->
+
+## Tasks
+
+<!--
+Breakdown of the work
+- [ ] Task 1
+- [ ] Link to GitHub issue tracking task 2
+-->
+
+# RAID (Risks, Assumptions, Issues and Dependencies)
+
+<!-- List dependencies on other epics (avoid dependencies on tasks) -->
+
+<!-- List dependencies on other teams -->
+
+<!-- List any risks or assumptions that will be cleared as work progresses -->
+
+<!-- List any GitHub issues that tracks any blocker or any of the items above -->

.github/ISSUE_TEMPLATE/milestone.md

@@ -1,40 +0,0 @@
----
-name: Milestone
-about: Track Milestones
-title: "[Milestone] "
-labels: milestone
-assignees: ''
-
----
-
-<!-- Please ensure you are assigning the matching epic label to the milestone -->
-<!-- All _active_ (being worked on) milestones MUST have an owner (GitHub assignee) -->
-
-**Planned start date**:
-**Due date**:
-
-# Summary
-
-<!-- Provide a high level summary of the Milestone -->  
-
-# Acceptance Criteria
-
-<!-- describe the deliverable of this milestone and its attributes in plain English -->
-
-## Tasks
-
-<!--
-Breakdown of the work
-- [ ] Task 1
-- [ ] Link to GitHub issue tracking task 2
--->
-
-# RAID (Risks, Assumptions, Issues and Dependencies)
-
-<!-- List dependencies on other milestones (avoid dependencies on tasks) -->
-
-<!-- List dependencies on other teams -->
-
-<!-- List any risks or assumptions that will be cleared as work progresses -->
-
-<!-- List any GitHub issues that tracks any blocker or any of the items above -->