Pseudopattern documentation. I really dont like including this here while not having a solution for patternlab.io documentation. may need to focus on that more.

Author: bmuenzenmeyer

README.md

@@ -73,6 +73,55 @@ Pattern states should be lowercase and use hyphens where spaces are present.
 }
 ```
 
+##### Pseudo-Patterns
+Pseudo-patterns are meant to give developers the ability to build multiple and unique **rendered** patterns off of one base pattern and its mark-up while giving them control over the data that is injected into the base pattern. This feature is especially useful when developing template- and page-style patterns.
+
+Pseudo-patterns are, essentially, the pattern-specific JSON files that would accompany a pattern. Rather than require a Mustache pattern, though, pseudo-patterns are hinted so a developer can reference a shared pattern. The basic syntax:
+
+`patternName~pseudoPatternName.json`
+
+The tilde, `~`, and JSON extension denotes that this is a pseudo-pattern. `patternName` is the parent pattern that will be used when rendering the pseudo-pattern. `patternName` and `pseudoPatternName` are combined when adding the pseudo-pattern to the navigation.
+
+The JSON file itself works exactly like the [pattern-specific JSON file](http://patternlab.io/docs/data-pattern-specific.html). It has the added benefit that the pseudo-pattern will also import any values from the parent pattern's pattern-specific JSON file. Here is an example (which ships with the package) where we want to show an emergency notification on our homepage template. Our `03-templates/` directory looks like this:
+
+```
+00-homepage.mustache
+01-blog.mustache
+02-article.mustache
+```
+
+Our `00-homepage.mustache` template might look like this:
+
+```
+<div id="main-container">
+    {{# emergency }}
+        <div class="emergency">Oh Noes! Emergency!</div>
+    {{/ emergency }}
+    { ...a bunch of other content... }
+</div>
+```
+
+If our `_data.json` file doesn't give a value for `emergency` that section will never show up when `00-homepage.mustache` is rendered.
+
+We want to show both the regular and emergency states of the homepage but we don't want to duplicate the entire `00-homepage.mustache` template. That would be a maintenance nightmare. So let's add our pseudo-pattern:
+
+```
+00-homepage.mustache
+00-homepage~emergency.json
+01-blog.mustache
+02-article.mustache
+```
+
+In our pseudo-pattern, `00-homepage~emergency.json`, we add our `emergency` attribute:
+
+```
+{
+    "emergency": true
+}
+```
+
+Now when we generate our site we'll have our homepage template rendered twice. Once as the regular template and once as a pseudo-pattern showing the emergency section. Note that the pseudo-pattern will show up in our navigation as `Homepage Emergency`.
+
 ##### Pattern Linking
 You can build patterns that link to one another to help simulate using a real website. This is especially useful when working with the Pages and Templates pattern types. The basic format is: