add conduit::utils::format

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project aspires to adhere to [Semantic Versioning](https://semver.org/s
 - Added a builtin sandboxed header-only version of fmt. The namespace and directory paths were changed to `conduit_fmt` to avoid potential symbol collisions with other codes using fmt. Downstream software can use by including `conduit_fmt/conduit_fmt.h`.
 - Added support for using C++11 initializer lists to set Node and DataArray values from numeric arrays. See C++ tutorial docs (https://llnl-conduit.readthedocs.io/en/latest/tutorial_cpp_numeric.html#c-11-initializer-lists) for more details.
 - Added a Node::describe() method. This method creates a new node that mirrors the current Node, however each leaf is replaced by summary stats and a truncated display of the values. For use cases with large leaves, printing the describe() output Node is much more helpful for debugging and understanding vs wall of text from other to_string() methods. 
+- Added conduit::utils::format methods. These methods use fmt to format strings that include fmt style patterns. The formatting argments are passed as a conduit::Node tree. The `args` case allows named arguments (args passed as object) or ordered args (args passed as list). The `maps` case also supports named or ordered args and works in conjunction with a `map_index`. The `map_index` is used to fetch a value from an array, or list of strings, which is then passed to fmt. The `maps` style of indexed indirection supports generating path strings for non-trivial domain partition mappings in Blueprint.
 
 
 #### Relay