Add a length check of non-comment lines in C/C++ to the cookbook (#89)

Co-authored-by: Johannes Maron <johannes@maron.family>

COOKBOOK.md

@@ -7,6 +7,7 @@ A collection of recipes for reLint. Please feel free to contribute!
 - [Python](#python)
  - [Django](#django)
 - [HTML](#html)
+- [C/C++](#cc)
 
 # Python
 
@@ -104,3 +105,14 @@ A collection of recipes for reLint. Please feel free to contribute!
  You may use a CSS class instead.
  filePattern: .*\.(html|vue|jsx|tsx)
 ```
+
+# C/C++
+
+```yaml
+# This rule requires you to install the extra `regex` dependency.
+- name: no line longer than 120 characters in a line (excluding comments) # by @yangcht
+ pattern: '(?<!^[ \u00A0\u1680\u2000-\u200A\u202F\u205F\u3000]*//.*)(?<!/\*(?:(?!\*/)[\s\S\r])*?)\b(.{120,})\b'
+ hint: |
+ Please do not use more than 120 characters in codes except for comments.
+ filePattern: .*\.(C|cc|cxx|cpp|c++|cppm)
+```