features (toc):

add toc on navigation section
Merge branch 'master' into tco
anchor navigation

- platform
- system-images
fix(navbar): dynamic navigation

Navigation menu automatically render base from pages.
page(build-tool): initial page
pages(content): add description

Markdown content for each pages
pages(installation): add docs install location
pages(documentation): add documentation download page
fix(navbar): change to data.section
features(page): add source page

Each source required to develop an app. Default installed SDK already have latest version of this.
fix(navbar): relative link when add getting-start
release(viewer): v0.1.0