add language config

Signed-off-by: Toshaan Bharvani <toshaan@vantosh.com>

config/_default/config.toml

@@ -2,7 +2,10 @@
 title = "OpenPOWER Foundation"
 baseURL = "https://openpower.foundation/"
 theme = "openpowerfoundation"
-languageCode = "en-us"
+languageCode = "opf"
+defaultContentLanguage = "opf"
+defaultContentLanguageInSubdir = true
+enableMissingTranslationPlaceholders = true
 dataDir = "data"
 assetDir = "assets"
 PaginatePath = ""