Add more information to the blog guide

docs/guides-blog.md

@@ -12,7 +12,7 @@ Then, add a header link to your blog within `siteConfig.js`:
 ```
 headerLinks: [
     ...
-    {href: '/blog', label: 'Blog'},
+    {blog: true, label: 'Blog'},
     ...
 ]
 ```
@@ -21,7 +21,6 @@ headerLinks: [
 
 To publish in the blog, create a file within the blog folder with a formatted name of `YYYY-MM-DD-My-Blog-Post-Title.md`. The post date is extracted from the file name.
 
-
 For example, we will create the following file `website/blog/2017-08-18-Introducing-Docusaurus.md`:
 
 ```
@@ -35,9 +34,32 @@ title: Introducing Docusaurus
 Lorem Ipusm..
 ```
 
+## Blog Post Summaries
+
+Use the `<!--truncate-->` marker in your blog post to represent what will be shown as the summary when viewing all blog published blog posts. Anything above `<!--truncate-->` will be part of the summary. For example:
+
+```
+---
+title: Truncation Exmaple
+---
+
+All this will be part of the blog post summary.
+
+Even this.
+
+<!--truncate-->
+
+But anything from here on down will not be.
+
+Not this.
+
+Or this.
+```
 ## Special blog post header options
 
-- `author` - The text label of the author byline
+The only required field is `title`; however, we provide options to add author information to your blog post as well.
-- `authorURL` - The url that the author name links to
+
-- `authorFBID` - The Facebook ID that is used to extract the profile picture
+- `author` - The text label of the author byline.
-- `title` - The blog post title
+- `authorURL` - The url associated with the author. This could be a Twitter, GitHub, Facebook account, etc.
+- `authorFBID` - The Facebook ID that is used to extract the profile picture.
+- `title` - The blog post title.