feat(v4): adjust update-demo-page.yml (#570)

Author: igor-baiborodine

.github/workflows/update-demo-page.yml

@@ -36,7 +36,7 @@ jobs:
         run: hugo new site /tmp/demo-site
 
       - name: Copy exampleSite content to new site
-        run: cp -r ./exampleSite/* /tmp/demo-site
+        run: cp -r ./v4/exampleSite/* /tmp/demo-site
 
       - name: Init Hugo module
         working-directory: /tmp/demo-site
@@ -49,7 +49,7 @@ jobs:
         working-directory: /tmp/demo-site
         run: |
           sed -i "s/baseURL = .*$/baseURL = \"https:\/\/lednerb.github.io\/bilberry-hugo-theme\/\"/" config.toml
-          version=$(grep -o 'v[0-9]\.[0-9][0-9]\.[0-9]' go.mod)
+          version=$(grep -Po "(?<=v4\s)[^\s//]+" go.mod)
           sed -i "s/creditsText = .*$/creditsText = \"Bilberry Hugo Theme $version\"/" config.toml
           sed -i "s/creditsUrl = .*$/creditsUrl = \"https:\/\/github.com\/Lednerb\/bilberry-hugo-theme\/tree\/$version\"/" config.toml