Bump version to v21.1 for release

Summary:
  * Change memory per node for `sbatch` runs to 0 to ensure that jobs go on to
    the "by-node" queue on `graham`.
  * Rename Git default branch from `master` to `main`.
  * Change continuous integration from Bitbucket pipeline to GitHub Actions
    workflow.
  * Migrate from Mercurial on Bitbucket to Git on GitHub due to Bitbucket's
    decision to terminate support for Mercurial.
  * Expose `nemo_cmd.prepare.record_vcs_revisions()`` function for use by
    packages like MOHID-Cmd that extend NEMO-Cmd.
  * Enable version control system (VCS) revision recording for Git repositories.
  * Replace `namelist.py` module with `f90nml` package.
  * Change to new MOAD package layout.

Please see docs/CHANGES.rst for more details.

docs/CHANGES.rst

@@ -2,17 +2,16 @@
 Change Log
 **********
 
+v21.1 (2021-10-21)
+==================
 
-v21.1.dev0 (unreleased)
-=======================
-
-* Change memory per node for `sbatch` runs to 0 to ensure that jobs go on to the "by-node"
-  queue on `graham`.
-  The queue selection algorithm in the scheduler on `graham` appears to have changed
+* Change memory per node for ``sbatch`` runs to 0 to ensure that jobs go on to the "by-node"
+  queue on ``graham``.
+  The queue selection algorithm in the scheduler on ``graham`` appears to have changed
   (without announcement) on 13-Jul-2021 so that the previous memory per node of 125G
   now sends jobs to the "by-core" queue which is generally more crowded.
 
-* Rename Git default branch from `master` to `main`.
+* Rename Git default branch from ``master`` to ``main``.
 
 * Change continuous integration from Bitbucket pipeline to GitHub Actions workflow.
   CI reports are at https://github.com/SalishSeaCast/NEMO-Cmd/actions

nemo_cmd/__init__.py

@@ -12,7 +12,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-__version__ = "21.1.dev0"
+__version__ = "21.1"
 
 
 # Make fspath.fspath() and fspath.resolved_path() available in the nemo_cmd