Add a section of conformant ways to go about "calling" an algorithm

[igneel64]

Currently in the spec I have not found a place that guides individuals on how to "call" a defined algorithm in a conformant way.

There are many places in the example that algorithms are called but I failed to find a formula for it. The pattern that I see most is: Return the result of X-ALGORITHM, given Y.

In my opinion adding that will be really helpful, cheers!

If I have missed any open issue or a reference in the spec, please let me know

[annevk]

Note that #325 goes a long way toward this in terms of algorithm arguments and examples of what we expect. Ensuring algorithms are linked to a definition is also somewhat vital for readers.