Merge branch 'jc/how-to-document-api' into maint

Doc update.

* jc/how-to-document-api:
  CodingGuidelines: document the API in *.h files

Documentation/CodingGuidelines

@@ -358,7 +358,10 @@ For C programs:
    string_list for sorted string lists, a hash map (mapping struct
    objects) named "struct decorate", amongst other things.
- - When you come up with an API, document it.
+ - When you come up with an API, document its functions and structures
+   in the header file that exposes the API to its callers. Use what is
+   in "strbuf.h" as a model for the appropriate tone and level of
+   detail.
  - The first #include in C files, except in platform specific compat/
    implementations, must be either "git-compat-util.h", "cache.h" or