Add theme

Author: abhinavj98

.github/workflows/docs.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install sphinx
+          pip install sphinx sphinx_rtd_theme
           # add any extensions you use, e.g.:
           # pip install myst-parser sphinx_rtd_theme