Add demosite link to theme.toml (adityatelange#1724)

Author: bep

theme.toml

@@ -6,6 +6,7 @@ license = "MIT"
 licenselink = "https://github.com/adityatelange/hugo-PaperMod/blob/master/LICENSE"
 description = "A fast, clean, responsive Hugo theme"
 homepage = "https://adityatelange.github.io/hugo-PaperMod/"
+demosite = "https://adityatelange.github.io/hugo-PaperMod/"
 tags = [
   "responsive",
   "simple",