adding .dev towncrier category to the release notes

- the aim is to link  merged PRs to WIP features so that every change is traceable to every release

CONTRIBUTING.md

@@ -61,6 +61,7 @@ Supported filename extensions are:
 
 - ``.feature``: Signifying a new feature in Element Android or in the Matrix SDK.
 - ``.bugfix``: Signifying a bug fix.
+- ``.dev``: Signifying a change which is not ready to be user facing, typically a component of a larger feature.
 - ``.doc``: Signifying a documentation improvement.
 - ``.removal``: Signifying a deprecation or removal of public API. Can be used to notifying about API change in the Matrix SDK
 - ``.misc``: Any other changes.

towncrier.toml

@@ -15,6 +15,11 @@
         name = "Bugfixes 🐛"
         showcontent = true
 
+    [[tool.towncrier.type]]
+        directory = "dev"
+        name = "In development"
+        showcontent = true
+
     [[tool.towncrier.type]]
         directory = "doc"
         name = "Improved Documentation 📚"