Promote @dwreeves to committer (astronomer#960)

[Daniel Reeves](https://www.linkedin.com/in/daniel-reeves-27700545/)
(@dwreeves ) is an experienced Open-Source Developer currently working
as a Data Architect at Battery Ventures. He has significant experience
with Apache Airflow, SQL, and Python and has contributed to many [OSS
projects](https://github.com/dwreeve).

Not only has he been using Cosmos since its early stages, but since
January 2023, he has actively contributed to the project:
![Screenshot 2024-05-14 at 10 47
30](https://github.com/astronomer/astronomer-cosmos/assets/272048/57829cb6-7eee-4b02-998b-46cc7746f15a)

He has been a critical driver for the Cosmos 1.4 release, and some of
his contributions include new features, bug fixes, and documentation
improvements, including:
* Creation of an Airflow plugin to render dbt docs:
astronomer#737
* Support using dbt partial parsing file:
astronomer#800
* Add more template fields to `DbtBaseOperator`:
astronomer#786
* Add cancel on kill functionality:
astronomer#101
* Make region optional in Snowflake profile mapping:
astronomer#100
* Fix the dbt docs operator to not look for `graph.pickle`:
astronomer#883

He thinks about the project long-term and proposes thorough solutions to
problems faced by the community, as can be seen in Github tickets:
* Introducing composability in the middle layer of Cosmos's API:
astronomer#895
* Establish a general pattern for uploading artifacts to storage:
astronomer#894
* Support `operator_arguments` injection at a node level:
astronomer#881

One of Daniel's notable traits is his collaborative and supportive
approach. He has actively engaged with users in the #airflow-dbt Slack
channel, demonstrating his commitment to fostering a supportive
community.

We want to promote him as a Cosmos committer and maintainer for all
these, recognising his constant efforts and achievements towards our
community. Thank you very much, @dwreeves !

docs/contributors.rst

@@ -9,6 +9,7 @@ Committers
 ----------------------
 
 * Chris Hronek (`@chrishronek <https://github.com/chrishronek>`_)
+* Daniel Reeves (`@dwreeves <https://github.com/dwreeves>`_)
 * Harel Shein (`@harels <https://github.com/harels>`_)
 * Julian LaNeve (`@jlaneve <https://github.com/jlaneve>`_)
 * Justin Bandoro (`@jbandoro <https://github.com/jbandoro>`_)