Fix minor things in <dfn> documentation, add <u> & <dfn> to docs/components README

Author: pascalwengerter

docs/components/README.md

@@ -21,6 +21,7 @@ You can build your [own components](/docs/extend/README.md) as well, both static
 - [cite](/docs/components/cite.md)
 - [code](/docs/components/code.md)
 - [data](/docs/components/data.md)
+- [dfn](/docs/components/dfn.md)
 - [dl](/docs/components/dl.md)
   - dd
   - dt
@@ -76,6 +77,7 @@ You can build your [own components](/docs/extend/README.md) as well, both static
   - th
   - tr
   - td
+- [u](/docs/components/u.md)
 - [var](/docs/components/var.md)
 - [video](/docs/components/video.md)
 - [youtube](/docs/components/youtube.md)

docs/components/dfn.md

@@ -1,12 +1,12 @@
-# matestack core component: Hr
+# matestack core component: Dfn
 
 Show [specs](/spec/usage/components/dfn_spec.rb)
 
 The HTML `<dfn>` tag implemented in ruby.
 
 ## Parameters
 
-This component can take 2 optional configuration params.
+This component can take 2 optional configuration params and either yield content or display what gets passed to the `text` configuration param.
 
 #### # id (optional)
 Expects a string with all ids the dfn should have.
@@ -19,15 +19,17 @@ Adding an optional id
 
 ```ruby
 div id: "foo", class: "bar" do
-  dfn id: "dfn-id"
+  dfn id: "dfn-id" do
+    plain 'Example'
+  end
 end
 ```
 
 returns
 
 ```html
 <div id="foo" class="bar">
-  <dfn id="dfn-id">
+  <dfn id="dfn-id">Example</dfn>
 </div>
 ```
 
@@ -36,14 +38,14 @@ Adding an optional class
 
 ```ruby
 div id: "foo", class: "bar" do
-  dfn class: "dfn-class"
+  dfn class: "dfn-class", text: 'Example'
 end
 ```
 
 returns
 
 ```html
 <div id="foo" class="bar">
-  <dfn class="dfn-class">
+  <dfn class="dfn-class">Example</dfn>
 </div>
 ```