Simplify PR template; add a template for changelog entries

.github/PULL_REQUEST_TEMPLATE

@@ -1,16 +1,15 @@
-# PR: Short description of change
-
 ## Description
 
-A clear and concise description of what the PR does and why.
+What changes and why
 
 ## Checklist
 
 - [ ] I have read followed [CONTRIBUTING.md](https://github.com/PJK/libcbor/blob/master/CONTRIBUTING.md)
 	- [ ] I have added tests
 	- [ ] I have updated the documentation
 	- [ ] I have updated the CHANGELOG
-- [ ] Are there any breaking changes? If so, are they documented?
-- [ ] Does this PR introduce any platform specific code? If so, is this captured in the description?
-- [ ] Security: Does this PR potentially affect security? If so, is this captured in the description?
-- [ ] Performance: Does this PR potentially affect performance? If so, is this captured in the description?
+- [ ] Are there any breaking changes?
+	- [ ] If yes: I have marked them in the CHANGELOG ([example](https://github.com/PJK/libcbor/blob/87e2d48a127968d39f158cbfc2b79d6285bd039d/CHANGELOG.md?plain=1#L16))
+- [ ] Does this PR introduce any platform specific code?
+- [ ] Security: Does this PR potentially affect security?
+- [ ] Performance: Does this PR potentially affect performance?

CHANGELOG.md

@@ -1,3 +1,6 @@
+Template:
+- [Fix issue X in feature Y](https://github.com/PJK/libcbor/pull/XXX) (by [YYY](https://github.com/YYY))
+
 Next
 ---------------------
 - Make the buffer_size optional in `cbor_serialize_alloc` [[#205]](https://github.com/PJK/libcbor/pull/205) (by [hughsie](https://github.com/hughsie))
@@ -7,7 +10,7 @@ Next
 - BUILD BREAKING: Minimum CMake version is 3.0 [[#201]](https://github.com/PJK/libcbor/pull/201) (by [thewtex@](https://github.com/thewtex))
   - See https://repology.org/project/cmake/versions for support; the vast majority of users should not be affected.
 - Fix a potential memory leak when the allocator fails during array or map decoding [[#224]](https://github.com/PJK/libcbor/pull/224) (by [James-ZHANG](https://github.com/James-ZHANG))
-- Fix a memory leak when the allocator fails when adding chunks to indefinite strings.
+- [Fix a memory leak when the allocator fails when adding chunks to indefinite strings.](https://github.com/PJK/libcbor/pull/228) (by [James-ZHANG](https://github.com/James-ZHANG))
 
 0.9.0 (2021-11-14)
 ---------------------