feat(website): migrates nav data format and updates docs pages (#1049)

* migrates nav data format and updates docs pages

* removes sidebar_title from content files

* updates api docs to work with new format

website/content/docs/developing/building.mdx

@@ -1,7 +1,6 @@
 ---
 layout: docs
 page_title: Documentation
-sidebar_title: Building
 description: Building Boundary
 ---
 

website/content/docs/developing/index.mdx

@@ -1,7 +1,6 @@
 ---
 layout: docs
 page_title: Developing Boundary
-sidebar_title: Developing Boundary
 description: Developing Boundary
 ---
 

website/content/docs/developing/ui.mdx

@@ -1,7 +1,6 @@
 ---
 layout: docs
 page_title: Developing the UI
-sidebar_title: Developing the UI
 description: Developing the Boundary User Interface
 ---