[wip] more updates to JSON schema for MLM definitions

CHANGELOG.md

@@ -18,19 +18,26 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - add `scene-classification` to the Enum Tasks to allow disambiguation between pixel-wise and patch-based classification
 
 ### Changed
-- reorganized `dlm:architecture` nested fields to exist at the top level of properties as `mlm:name`, `mlm:summary` and so on to provide STAC API search capabilities.
+- reorganized `dlm:architecture` nested fields to exist at the top level of properties as `mlm:name`, `mlm:summary`
+  and so on to provide STAC API search capabilities.
 - replaced `normalization:mean`, etc. with [statistics](./README.md#bands-and-statistics) from STAC 1.1 common metadata
 - added `pydantic` models for internal schema objects in `stac_model` package and published to PYPI
 - specified [rel_type](./README.md#relation-types) to be `derived_from` and specify how model item or collection json should be named
 - replaced all Enum Tasks names to use hyphens instead of spaces
 - replaced `dlm:task` by `mlm:tasks` using an array of value instead of a single one, allowing models to represent
   multiple tasks they support simultaneously or interchangeably depending on context
+- replace `pre_processing_function` and `post_processing_function` to use similar definitions
+  to the [Processing Extension - Expression Object](https://github.com/stac-extensions/processing#expression-object)
+  such that more extended definitions of custom processors can be defined.
+- updated JSON schema to reflect changes of MLM fields
 
 ### Deprecated
--
+- any `dlm`-prefixed field or property
 
 ### Removed
-- Data Object, replaced with [Model Input Object](./README.md#model-input-object) that uses the `name` field from the [common metadata band object](https://github.com/radiantearth/stac-spec/blob/f9b3c59ba810541c9da70c5f8d39635f8cba7bcd/item-spec/common-metadata.md#bands) which also records `data_type` and `nodata` type
+- Data Object, replaced with [Model Input Object](./README.md#model-input-object) that uses the `name` field from 
+  the [common metadata band object](https://github.com/radiantearth/stac-spec/blob/f9b3c59ba810541c9da70c5f8d39635f8cba7bcd/item-spec/common-metadata.md#bands) 
+  which also records `data_type` and `nodata` type
 
 # TODO link release here