Add extended API documentation

[c0riolis]

• Do the required Jekyll changes
• Fix relative links
• Document Group concept & aligned_size_t
• Add missing examples
• Verify that all examples are compiling

[c0riolis]

I think this is ready to be reviewed in depth.

The rendered version of this PR is available here:
https://draft.dll.pe/

Note: I left the cuda::memcpy_async example as a To-Do since @gonzalobg wanted to take a stab at it in PR #70 .

[hcedwar]

Given that memcpy_async is supposed to be a replacement for assigning from global memory to shared memory ( #53 (comment) ) the statement
The implementation may perform the copy synchronously in some implementation defined cases.
is inadequate for users to understand when asynchronous functionality is or is not possible.
Emphasis should be on how GPU customer-developers can obtain value (asynchronous functionality), not on how to introduce minimal wording change from std::memcpy.

[griwes]

@hcedwar thanks, that's good feedback, but can you contribute to the long comment thread above? Thanks!

[c0riolis]

Thanks for the review @griwes, I addressed most of your comments and replied to a couple of others for clarification. The PR / preview now reflects those changes.

[c0riolis]

Given that memcpy_async is supposed to be a replacement for assigning from global memory to shared memory ( #53 (comment) ) the statement
The implementation may perform the copy synchronously in some implementation defined cases.
is inadequate for users to understand when asynchronous functionality is or is not possible.
Emphasis should be on how GPU customer-developers can obtain value (asynchronous functionality), not on how to introduce minimal wording change from std::memcpy.

@hcedwar: I do not think that this is the role of this document to specify in which cases the implementation actually exhibits asynchronous behavior, especially since it varies depending on the architecture.

In my opinion, this information belongs to one of our other guides (programming guide, best practices guide, architecture-specific tuning guide).

[gonzalobg]

Thank you @c0riolis for doing all this work, the new docs look great!