Update pull_request_template.md

.github/pull_request_template.md

@@ -12,6 +12,7 @@
 * [ ] Output-parameter pointers in functions are on the left
 * [ ] Negative return values on failure of API functions (within restrictions of FO transform).
 * [ ] `const` arguments are labeled as `const`
-* [ ] (optional) All integer types are of fixed size, using `stdint.h` types (including `uint8_t` instead of `unsigned char`)
-* [ ] Integers used for indexing are of size `size_t`
 * [ ] variable declarations at the beginning (except in `for (size_t i=...`)
+* Optional:
+  * [ ] All integer types are of fixed size, using `stdint.h` types (including `uint8_t` instead of `unsigned char`)
+  * [ ] Integers used for indexing are of size `size_t`