Update more broken URLs and a README

Documentation/NuttXGettingStarted.html

@@ -18,7 +18,7 @@
   There is no "Getting Started" Guide for NuttX yet.
   However, most everything that you need to get started with NuttX can be found in the <code>README.txt</code> file located in the top-level NuttX directory.
   That <code>README.txt</code> can also be read online in the NuttX GIT repository
-  <a href="http://sourceforge.net/p/nuttx/git/ci/master/tree/nuttx/README.txt">here</a>.
+  <a href="http://sourceforge.net/p/nuttx/git/ci/master/tree/nuttx/README.txt" target="_blank">here</a>.
   Just click on &quot;Links to HEAD: (view)&quot; on that page.
 </p>
 </body>

README.txt

@@ -13,6 +13,7 @@ README
     - Refreshing Configurations
     - NuttX Configuration Tool
     - Finding Selections in the Configuration Menus
+    - Reveal Hidden Configuration Options
     - Comparing Two Configurations
     - Incompatibilities with Older Configurations
     - NuttX Configuration Tool under DOS
@@ -443,6 +444,18 @@ NuttX Configuration Tool
 
     make gconfig
 
+  Some keyboard shortcus supported by kconfig-mconf, the tool that runs
+  when you do 'make menuconfig':
+
+    - '?' will bring up the mconfig help display.
+
+    - '/' can be used find configuration selections.
+
+    - 'Z' can be used to reveal hidden configuration options
+
+  These last to shortcuts are described further in the following
+  paragraphs.
+
 Finding Selections in the Configuration Menus
 ---------------------------------------------
 
@@ -459,6 +472,23 @@ Finding Selections in the Configuration Menus
   It will show you not only where to find the configuration item, but
   also all of the dependencies related to the configuration item.
 
+Reveal Hidden Configuration Options
+-----------------------------------
+
+  If you type 'Z', then kconfig-mconf will change what is displayed.
+  Normally, only enabled features that have all of their dependencies met
+  are displayed.  That is, of course, not very useful if you would like to
+  discover new options or if you are looking for an option and do not
+  realize that the dependencies have not yet been selected and, hence, it
+  is not displayed.
+
+  But if you enter 'Z', then every option will be shown, whether or not its
+  dependencies have been met.  You can the see everything that could be
+  selected with the right dependency selections.  These additional options
+  will be shown the '-' for the selection and for the value (since it
+  cannot be selected and has no value).  About all you do is to select
+  the <Help> option to see what the dependencies are.
+
 Comparing Two Configurations
 ----------------------------