Move the content of dotkernel.org to dotkernel.com/api

[arhimede]

create a separate static page

with a special route dotkernel.com/page/api to be dotkernel.com/api

add on it most of the content from https://www.dotkernel.org/ and curated

[bidi47]

opted for a new page instead: /architecture/
the new page describes the architecture and contains the execution flow diagrams

the current api page is more current, so it remains the main page for describing the api as a product
note some content from dk.org that was not covered by the api page was merged into it (route:list, dot-mail/email, DeprecationMiddleware)