Add three new doc pages to the website.
- A containerd quick start covering containerd 1.2. This is limited to shim v2
and runtime class as the docs would get too complicated explaining all the
combinations that are possible. We want folks to use shim v2 and runtime
class anyway.
- An advanced configuration page. This covers containerd and
containerd-shim-runsc-v1's configuration options.
- A page for old versions (i.e. containerd 1.1). Notes that this is deprecated
and supported on a best-effort basis.
Fixes#3279
PiperOrigin-RevId: 324775563
Ian Lewis