Fix RTD deprecation notice (#1803)

This PR:
- describes the `requirements.txt` file for RTD documentation deprecation notice described in issue #1798 

fixes #1798

.pycodestyle

@@ -3,4 +3,4 @@ count = False
 ignore = E402,W504
 max-line-length = 160
 statistics = True
-exclude = Experimental,.git,.vscode,*.fd,*.cd
+exclude = .git,.github,.vscode,venv,*.fd,*.cd,docs/source/conf.py

.readthedocs.yaml

@@ -15,7 +15,9 @@ build:
 sphinx:
   configuration: docs/source/conf.py
 
+# Optional but recommended, declare the Python requirements required
+# to build your documentation
+# See https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html
 python:
   install:
     - requirements: docs/requirements.txt
-  system_packages: true

docs/requirements.txt

@@ -1,2 +1,5 @@
-sphinxcontrib-bibtex
+sphinx
 sphinx_rtd_theme
+sphinxcontrib-bibtex
+sphinx-autobuild
+sphinx-copybutton

docs/source/conf.py

@@ -80,7 +80,17 @@
 # documentation.
 #
 # html_theme_options = {}
-html_theme_options = {"body_max_width": "none"}
+html_theme_options = {"body_max_width": "none",
+                      "footer_icons": [
+    {"name": "GitHub",
+     "url": "https://github.com/NOAA-EMC/global-workflow",
+     "html": """
+            <svg stroke="currentColor" fill="currentColor" stroke-width="0" viewBox="0 0 16 16">
+                <path fill-rule="evenodd" d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27.68 0 1.36.09 2 .27 1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.013 8.013 0 0 0 16 8c0-4.42-3.58-8-8-8z"></path>
+            </svg>
+             """,
+     "class": ""}]
+                      }
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,