Fix "bad substitution error"

Author: SemyonSinchenko

.github/workflows/docs.yml

@@ -36,4 +36,4 @@ jobs:
           
       - name: Build and Deploy
         run:
-          ${poetry env info --path -C ${{ github.workspace }}/tsumugi-python}/bin/mkdocs gh-deploy --force
+          $(poetry env info --path -C ${{ github.workspace }}/tsumugi-python)/bin/mkdocs gh-deploy --force