Docs: Added hasCJKLanguage global config flag and isCJKLanguage FrontMatter

See #1399

docs/content/content/front-matter.md

@@ -95,6 +95,7 @@ Field names are always normalized to lowercase (e.g. `camelCase: true` is availa
 * **draft** If true, the content will not be rendered unless `hugo` is called with `--buildDrafts`
 * **publishdate** If in the future, content will not be rendered unless `hugo` is called with `--buildFuture`
 * **type** The type of the content (will be derived from the directory automatically if unset)
+* **isCJKLanguage** If true, explicitly treat the content as CJKLanguage (.Summary and .WordCount can work properly in CJKLanguage)
 * **weight** Used for sorting
 * **markup** *(Experimental)* Specify `"rst"` for reStructuredText (requires
             `rst2html`) or `"md"` (default) for Markdown

docs/content/overview/configuration.md

@@ -135,6 +135,8 @@ Following is a list of Hugo-defined variables that you can configure and their c
     uglyURLs:                   false
     # Do not make the url/path to lowercase
     disablePathToLower:         false
+    # if true, auto-detect Chinese/Janapese/Korean Languages in the content. (.Summary and .WordCount can work properly in CJKLanguage)
+    hasCJKLanguage              false
     # verbose output
     verbose:                    false
     # verbose logging