Update changelog

Author: FelonEkonom

CHANGELOG.md

@@ -7,6 +7,7 @@
 * Deprecate `:links` option for `:unsafely_name_processes_for_observer` in favour of `:report_links_to_observer` configuration entry
 * [Set label](https://hexdocs.pm/elixir/Process.html#set_label/1) for all the Membrane processes (i.e. for both Membrane components like pipelines, elements and bins and for utility components like subprocess supervisors)
 * Update required Elixir version to `~> 1.17`
+* Support input demand unit expressed in timestamps [#1079](https://github.com/membraneframework/membrane_core/pull/1079)
 
 ## 1.2.6
  * Add tutorials [#1007](https://github.com/membraneframework/membrane_core/pull/1007), plugins [#1012](https://github.com/membraneframework/membrane_core/pull/1012) and demos [#1013](https://github.com/membraneframework/membrane_core/pull/1013) to the docs.