minor documentation fixes (#505)

* fix incorrect language setting in sphinx documentation build
* changed name of branch in documentation to main
* turned on warnings as errors in doc build
---------

.github/workflows/docs.yml

@@ -36,7 +36,7 @@ jobs:
     - name: Build docs
       run: |
         cd rrfs-workflow/doc/UsersGuide
-        sphinx-build -b html source build
+        sphinx-build -W --keep-going source build
     - uses: actions/upload-artifact@v4
       with:
         name: rrfs-workflow docs

doc/UsersGuide/source/Quickstart.rst

@@ -12,11 +12,11 @@ This chapter provides a brief summary of how to build and run the RRFS-Workflow.
 Building RRFS workflow
 ===============================================
 
-   #. Clone the ``dev-sci`` branch of the RRFS-Workflow from GitHub:
+   #. Clone the ``main`` branch of the RRFS-Workflow from GitHub:
 
       .. code-block:: console
 
-         git clone -b dev-sci https://github.com/NOAA-EMC/rrfs-workflow.git
+         git clone https://github.com/NOAA-EMC/rrfs-workflow.git
 
    #. Check out the external components:
 

doc/UsersGuide/source/conf.py

@@ -73,7 +73,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = 'en'
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.