Place commit style guide properly

This project expects contributors to these additional rules.

Change-Id: I3d9411e792be96cd76873a70786f7d07cd89dc4c

Author: jserv

CONTRIBUTING.md

@@ -789,6 +789,34 @@ mainstream architectures.  PDP-11 era is long gone.
 - It is fair to assume that `NULL` is matching `(uintptr_t) 0` and it is fair
 to `memset()` structures with zero.  Non-zero `NULL` is for retro computing.
 
+## Commit Style
+
+Simple housekeeping for a clean git history. Read more on
+[How to Write a Git Commit Message](https://cbea.ms/git-commit/).
+1. Separate the subject from the body with a blank line.
+2. Limit the subject line to 50 characters.
+3. Capitalize the subject line.
+4. Do not end the subject line with a period.
+5. Use the imperative mood in the subject line.
+6. Wrap the body at 72 characters.
+7. Use the body to explain what and why, not how.
+
+In addition, this project expects contributors to follow these additional rules:
+* If there is important, useful, or essential conversation or information,
+  include a reference or copy it.
+* Do not write single-word commits. Provide a descriptive subject.
+* Avoid using just a filename (e.g., `Update qtest.c`).
+  Each commit message subject should be sufficiently descriptive.
+* Avoid using abusive words.
+* For queue functions (names starting with "q_", e.g., `Implement q_size` or `Finish q_new`),
+  ensure the commit message includes a detailed explanation in the body.
+* Avoid using backticks in commit subjects.
+  Backticks can be easily confused with single quotes on some terminals,
+  reducing readability. Plain text or single quotes provide sufficient clarity and emphasis.
+* Avoid using parentheses in commit subjects.
+  Excessive use of parentheses "()" can clutter the subject line,
+  making it harder to quickly grasp the essential message.
+
 ## References
 - [Linux kernel coding style](https://www.kernel.org/doc/html/latest/process/coding-style.html)
 - 1999, Brian W. Kernighan and Rob Pike, The Practice of Programming, Addison–Wesley.

scripts/commit-msg.hook

@@ -93,7 +93,7 @@ display_warnings() {
 
   echo
   echo -e "${RED}$(cat <<-EOF
-How to Write a Git Commit Message: https://chris.beams.io/posts/git-commit/
+Read https://github.com/sysprog21/lab0-c/blob/master/CONTRIBUTING.md#commit-style carefully.
 EOF
 )${NC}"
 }