docs: note about linking commit message to issue

A commit message must refer to problem that motivated its development.

Signed-off-by: Claudio André <[email protected]>

.github/pull_request_template.md

@@ -1,3 +1,11 @@
+---
+name: PR
+about: Create a pull request
+title: ""
+labels: ""
+assignees: ""
+---
+
 ## Describe your changes
 
 Add your text here.
@@ -13,3 +21,12 @@ Add your text here.
 - [ ] I have added tests that prove my fix is effective or that my feature works
 - [ ] New and existing unit tests pass locally with my changes
 - [ ] If it is a core feature, I have added comprehensive tests.
+- [ ] If the issue this PR refers to is a bug report, add the following text to each of the commits
+      that make it up:
+  - Fix #VALUE.
+- [ ]  If the issue this PR refers to is a feature request, add the following text to each of the
+       commits that make it up:
+  - Close #VALUE.
+- [ ]  Commits may not be exactly a fix or implementation of a feature, but they can be related
+       to any issue, in this case, add the following text to each of the commits that make it up:
+  - See #VALUE.

docs/commit-messages.md

@@ -11,6 +11,18 @@ The commit message must follow the format:
 - The body or description should be restricted to 72 characters per line.
   - It should explain the motivation for the change.
 
+A commit message must refer to its purpose and to the problem that motivated its development:
+
+- If the issue a commit refers to is a bug report, add the following text to the
+  commit message:
+  - Fix #VALUE.
+- If the issue a commit refers to is a feature request, add the following text to
+  the commit message:
+  - Close #VALUE.
+- Commits may not be exactly a fix or implementation of a feature, but they can be
+  related to any issue, in this case, add the following text to the commit message:
+  - See #VALUE.
+
 Examples:
 
 ```text