chore: update PR template and auto-assign sdk-team reviewers (#579)

* chore: adopt shared SDK PR template and auto-request sdk-team reviews

- Replace PR template with the shared SDK template
- Add workflow to request review from @Iterable/sdk-team on new PRs

* chore: require sdk-team review via CODEOWNERS instead of workflow

Author: joaodordio

.github/CODEOWNERS

@@ -1 +1,4 @@
-*                                   @mprew97
+# https://docs.github.com/articles/about-code-owners
+# Require review from the SDK team on every PR.
+
+* @Iterable/sdk-team

.github/pull_request_template.md

@@ -1,7 +1,19 @@
-## JIRA Ticket(s) if any
+# 📝 Summary
+> _This should be a 150 characters summary of the changes on this PR_
 
-* [MOB-XXXX](https://iterable.atlassian.net/browse/MOB-XXXX)
+###### 🎟️ Jira Ticket: [SDK-XXXX](https://iterable.atlassian.net/browse/SDK-XXXX)
 
-## Description
+## 📖 Description
+> Please provide a description of what this pull request does.
 
-## Test Steps
+## 🧪 How to test?
+> How to test the changes added?
+
+## 📹 Loom recording if applicable
+> If it helps the reviewer, add a short Loom going over the changes or showcasing the change in behavior.
+
+#### 🐞 Github Issues solved
+> If this solves any open GH Issues, please link them here.
+
+#### 📚 Docs PR if applicable
+> Open a PR on the [Docs Repo](https://github.com/Iterable/iterable-docs) documenting the changes.