doc: continue doc restructuring

Changing the folder structure will cause too many broken links for
external references (from other sites). So, let's put the content back
where it was before the reorg, and instead use the new persona-based
navigation to point to documents in the original locations.

Also, introduce redirects for some documents that no longer exits.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

doc/conf.py

@@ -36,7 +36,7 @@ if "RELEASE" in os.environ:
 
 sys.path.insert(0, os.path.join(os.path.abspath('.'), 'extensions'))
 extensions = ['breathe', 'sphinx.ext.graphviz', 'sphinx.ext.extlinks',
-              'kerneldoc', 'eager_only']
+              'kerneldoc', 'eager_only', 'html_redirects']
 
 # extlinks provides a macro template
 
@@ -301,3 +301,18 @@ breathe_projects = {
 }
 breathe_default_project = "Project ACRN"
 breathe_default_members = ('members', 'undoc-members', 'content-only')
+
+
+# Custom added feature to allow redirecting old URLs (caused by
+# reorganizing doc directories)
+#
+# list of tuples (old_url, new_url) for pages to redirect
+#
+# URLs must be relative to document root (with NO leading slash),
+# and without the html extension)
+html_redirect_pages = [
+   ('developer-guides/index', 'contribute/index'),
+   ('getting-started/index', 'try/index'),
+   ('user-guides/index', 'develop/index'),
+   ('release_notes', 'release_notes/index')
+   ]