Improve GitHub Flavored Markdown Docs (#8684)

Merge pull request 8684

docs/_docs/configuration/markdown.md

@@ -9,23 +9,24 @@ available.
 
 Kramdown is the default Markdown renderer for Jekyll, and often works well with no additional configuration. However, it does support many configuration options.
 
-### GitHub Flavored Markdown
+### Kramdown Processor
 
-Kramdown supports GitHub Flavored Markdown (GFM). To use GFM with Kramdown in Jekyll, add the following to your configuration.
+By default, Jekyll uses the [GitHub Flavored Markdown (GFM) processor](https://github.com/kramdown/parser-gfm) for Kramdown. (Specifying `input: GFM` is fine, but redundant.) GFM supports a couple additional Kramdown options, documented by [kramdown-parser-gfm](https://github.com/kramdown/parser-gfm). These options can be used directly in your Kramdown Jekyll config, like this:
 
 ```yaml
 kramdown:
-  input: GFM
-```
-
-GFM supports additional Kramdown options, documented at [kramdown-parser-gfm](https://github.com/kramdown/parser-gfm). These options can be used directly in your Kramdown Jekyll config, like this:
-
-```yaml
-kramdown:
-  input: GFM
   gfm_quirks: [paragraph_end]
 ```
 
+You can also change the processor used by Kramdown (as specified for the `input` key in the [Kramdown RDoc](https://kramdown.gettalong.org/rdoc/Kramdown/Document.html#method-c-new)). For example, to use the non-GFM Kramdown processor in Jekyll, add the following to your configuration.
+
+```yaml
+kramdown:
+  input: Kramdown
+```
+
+Documentation for Kramdown parsers is available in the [Kramdown docs](https://kramdown.gettalong.org/parser/kramdown.html). If you use a Kramdown parser other than Kramdown or GFM, you'll need to add the gem for it.
+
 ### Syntax Highlighting (CodeRay)
 
 To use the [CodeRay](http://coderay.rubychan.de/) syntax highlighter with Kramdown, you  need to add a dependency on the `kramdown-syntax-coderay` gem. For example, `bundle add kramdown-syntax-coderay`. Then, you'll be able to specify CodeRay in your `syntax_highlighter` config:

docs/_tutorials/convert-site-to-jekyll.md

@@ -181,22 +181,16 @@ If you don't specify a layout in your pages, Jekyll will simply render that page
 
 ## 4. Add a configuration file
 
-Add a `_config.yml` file in your root directory. In `_config.yml`, you can optionally specify the markdown filter you want. By default, [kramdown](https://kramdown.gettalong.org/) is used (without the need to specify it). If no other filter is specified, your config file will automatically apply the following as a default setting:
+Add a `_config.yml` file in your root directory. In `_config.yml`, you can optionally specify the markdown filter you want. By default, the [GitHub Flavored Markdown (GFM) processor](https://github.com/kramdown/parser-gfm) for [kramdown](https://kramdown.gettalong.org/) is used. If no other filter is specified, your config file will automatically apply the following as a [default](/docs/configuration/default/) setting:
 
 ```yaml
 markdown: kramdown
-```
-
-You can also specify [some options](https://kramdown.gettalong.org/converter/html.html) for kramdown to make it behave more like [GitHub Flavored Markdown (GFM)](https://github.github.com/gfm/):
-
-```yaml
 kramdown:
- input: GFM
+  input: GFM
- auto_ids: true
- hard_wrap: false
- syntax_highlighter: rouge
 ```
 
+You can find additional [Markdown Options](/docs/configuration/markdown/) in the Jekyll docs, though it's unlikely that you'll need them.
+
 ## 5. Test your pages
 
 Now run `jekyll serve` and toggle between your `index.html` and `about.html` pages. The default layout should load for both pages.