chore: adding issue template (#481)

.github/PULL_REQUEST_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+template_chooser:
+  enabled: true
+  default: "other.md"
+  choices:
+    - name: "New Helper"
+      file: "new_helper.md"
+    - name: "Other Changes"
+      file: "other.md"

.github/PULL_REQUEST_TEMPLATE/new_helper.md

@@ -0,0 +1,23 @@
+
+## Describe your changes
+
+...
+
+## Checklist before requesting a review
+
+- [ ] 👓 I have performed a self-review of my code
+- [ ] 👶 This helper does not already exist
+- [ ] 🧪 This helper is tested
+- [ ] 🏎️ My code limits memory allocation and is fast
+- [ ] 🧞‍♂️ This helper is immutable and my tests prove it
+- [ ] ✍️ I implemented the parallel and mutable variants
+- [ ] 📖 My helper has been added to README
+- [ ] 🔬 An example has been added to xxxxx_example_test.go
+- [ ] ⛹️ An example has been created on https://go.dev/play
+
+## Conventions
+
+- Returning `(ok bool)` is often better than `(err error)`
+- `panic(...)` must be limited
+- Helpers should allow batching (eg: receive variadic arguments)
+- Use an index at the end of the helper name to declare variants (eg: `lo.Must0`, `lo.Must1`, `lo.Must2`...)