pw_status: Consolidate Status docs

- Move the status description from C++ to the docs so there is a single
  description of the status codes that applies to all languages. This
  also allows anywhere in the docs / Doxygen comments to link to the
  status codes.
- Document using status codes in all supported languages.
- Link to the status descriptions in Pigweed's docs from C++, Python,
  and TypeScript.
- Introduce Doxygen alias so status codes can be referenced with
  @pw_status{CODE} in Doxygen comments.

Change-Id: I7a59bc90da9cec09a08376952cf8472e02c67f03
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/136732
Pigweed-Auto-Submit: Wyatt Hepler <hepler@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: Kayce Basques <kayce@google.com>

docs/BUILD.gn

@@ -138,6 +138,7 @@ _doxygen_input_files = [
   "$dir_pw_sync/public/pw_sync/borrow.h",
   "$dir_pw_sync/public/pw_sync/counting_semaphore.h",
   "$dir_pw_sync/public/pw_sync/inline_borrowable.h",
+  "$dir_pw_status/public/pw_status/status.h",
   "$dir_pw_sync/public/pw_sync/interrupt_spin_lock.h",
   "$dir_pw_sync/public/pw_sync/lock_annotations.h",
   "$dir_pw_sync/public/pw_sync/mutex.h",

docs/Doxyfile

@@ -290,7 +290,8 @@ ALIASES                = "rst=^^\verbatim embed:rst:leading-asterisk^^" \
                          "c_macro{1}=@crossref{c,macro,\1}" \
                          "cpp_class{1}=@crossref{cpp,class,\1}" \
                          "cpp_func{1}=@crossref{cpp,func,\1}" \
-                         "cpp_type{1}=@crossref{cpp,type,\1}"
+                         "cpp_type{1}=@crossref{cpp,type,\1}" \
+                         "pw_status{1}=@crossref{c,enumerator,\1}"
 
 # Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C sources
 # only. Doxygen will then generate output that is more tailored for C. For
@@ -2390,7 +2391,7 @@ PREDEFINED             = __cplusplus \
                          PW_EXTERN_C_START= \
                          PW_LOCKS_EXCLUDED(...)= \
                          PW_EXCLUSIVE_LOCKS_REQUIRED(...)= \
-                         PW_GUARDED_BY(...)= \
+                         PW_GUARDED_BY(...)=
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The